File Types Dictionary

Comprehensive reference of all file extensions found in ConstructiVision v3.60 and v7.0 source distributions.

Note

This dictionary covers 51 unique file extensions found across both legacy versions. Each entry includes purpose, tooling, security considerations, and modern compatibility notes.

.$$$

Temporary/Backup File

Property

Value

Purpose

Temporary file created during save operations

Format

Binary (copy of original file)

Created By

Various applications during atomic save

Used By

Recovery processes

Found In

v3.60

Deprecation Status (2026): Still in use — common pattern for safe file saves

Security — Windows XP: No restrictions; temporary files often left in place with full permissions

Security — Windows 11 (2026): Same pattern still used; temp files may trigger antivirus scans

Compatibility: Universal — no compatibility issues

.AC$

AutoCAD Temporary File

Property

Value

Purpose

AutoCAD automatic save / backup file

Format

Binary (DWG format internally)

Created By

AutoCAD auto-save feature

Used By

AutoCAD recovery

Found In

v3.60

Deprecation Status (2026): Active — AutoCAD still creates these files

Security — Windows XP: No restrictions; often accumulates in drawing folders

Security — Windows 11 (2026): Same behavior; may be flagged by cleanup utilities

Compatibility: Rename to .dwg to recover; format matches AutoCAD version that created it

.ARX

AutoCAD Runtime Extension

Property

Value

Purpose

Native C++ plugin for AutoCAD (ObjectARX)

Format

Windows PE DLL (compiled C++)

Language

C++ with ObjectARX SDK

Created By

Visual C++, ObjectARX SDK

Used By

AutoCAD (loaded via (arxload))

Found In

v3.60 (pcms.arx, pcms2.arx)

Deprecation Status (2026): Active — ObjectARX still primary AutoCAD native API

Security — Windows XP:

  • No code signing required

  • Loaded directly into AutoCAD process space

  • Full system access when loaded

  • No execution policy restrictions

Security — Windows 11 (2026):

  • Code signing recommended (SmartScreen warnings)

  • Loaded into AutoCAD process (still full access)

  • Defender may quarantine unsigned ARX

  • ASLR/DEP apply to loaded modules

Compatibility:

  • ARX files are version-specific — must match AutoCAD version exactly

  • v3.60’s ARX built for AutoCAD R14/2000 will not load in AutoCAD 2020+

  • Requires recompilation with matching ObjectARX SDK

  • 32-bit ARX incompatible with 64-bit AutoCAD (2010+)

.BAK

Backup File

Property

Value

Purpose

Backup copy of edited file

Format

Same as original file

Created By

AutoCAD, text editors, various applications

Used By

Manual recovery

Found In

v3.60, v7.0

Deprecation Status (2026): Active — universal backup pattern

Security — Windows XP: No restrictions

Security — Windows 11 (2026): No restrictions; may contain sensitive data

Compatibility: Rename to original extension to use

.BHF

AutoCAD Big Help Font / Binary Help File

Property

Value

Purpose

Binary font/help index for AutoCAD add-in help system

Format

Proprietary binary (4,292 bytes; header 0x10 0xAB 0xAA 0xA8)

Created By

Autodesk help compiler or bundled with application

Used By

AutoCAD help system alongside CSV.Hlp

Found In

v7.0, v11 (CSV.BHF — ships in ConstructiVision install directory)

Deprecation Status (2026): Deprecated — WinHelp replaced by CHM, then web-based help. The underlying CSV.Hlp it supports is itself deprecated on Windows 10.

Security — Windows XP: Direct file access; no restrictions

Security — Windows 11 (2026): WinHelp engine removed; file is inert

Compatibility: Legacy only — modern AutoCAD uses web-based help. Harmless to keep in deployment (4 KB, no executable code).

Warning

Name collision: Symantec pcAnywhere also uses the .BHF extension for its “Binary Host File” (remote control host configuration). During Windows 7 testing, a monitoring tool observed a path C:\Documents and Settings\All Users\Application Data\Symantec\pcAnywhere\CSV.BHF — this was a pcAnywhere host file on the same test machine, not the ConstructiVision help file. The two formats are completely unrelated despite sharing the extension. pcAnywhere was part of the original XP test environment and may be relevant for understanding legacy deployment (see 22-windows10-upgrade-study § BHF Path Bug).

.BIN

Binary Data File

Property

Value

Purpose

Generic binary data storage

Format

Application-specific binary

Created By

Various applications

Used By

Application that created it

Found In

v3.60

Deprecation Status (2026): Active — generic extension still used

Security — Windows XP: No restrictions

Security — Windows 11 (2026): May trigger security scans; context-dependent

Compatibility: Application-specific; requires original software

.BK1

Secondary Backup File

Property

Value

Purpose

Additional backup (when .BAK exists)

Format

Same as original

Created By

Applications with multi-generation backup

Used By

Manual recovery

Found In

v3.60

Deprecation Status (2026): Uncommon — most apps use versioned backups now

Security: Same as .BAK

Compatibility: Rename to use

.BMP

Windows Bitmap Image

Property

Value

Purpose

Raster image storage

Format

Uncompressed bitmap (Windows DIB)

Created By

Paint, image editors, screen capture

Used By

Windows, image viewers, AutoCAD

Found In

v3.60, v7.0

Deprecation Status (2026): Active but declining — PNG/WebP preferred for quality/size

Security — Windows XP: Direct display; potential buffer overflow vectors (early parsers)

Security — Windows 11 (2026): Safe; modern parsers hardened

Compatibility: Universal — supported everywhere

.CAB

Microsoft Cabinet Archive

Property

Value

Purpose

Compressed archive for software distribution

Format

Microsoft Cabinet compression

Created By

MAKECAB.EXE, InstallShield, WiX

Used By

Windows Installer, setup programs

Found In

v3.60 (_sys1.cab, _user1.cab, data1.cab)

Deprecation Status (2026): Active — still used by Windows Update, MSI installers

Security — Windows XP:

  • Extracted with full permissions

  • No signature verification by default

  • InstallShield CABs have custom format extensions

Security — Windows 11 (2026):

  • Windows verifies signed CABs

  • SmartScreen checks extracted executables

  • Third-party CABs may trigger warnings

Compatibility:

  • Standard CABs extractable with expand.exe or 7-Zip

  • InstallShield CABs may require Unshield tool

  • v3.60 uses InstallShield 5.x format

.CIF

Component Information File

Property

Value

Purpose

InstallShield component metadata

Format

Text/binary hybrid

Created By

InstallShield compiler

Used By

InstallShield runtime

Found In

v3.60

Deprecation Status (2026): Deprecated — InstallShield formats evolved

Security: Part of installer; inherits installer security model

Compatibility: Legacy InstallShield only

.CTB

AutoCAD Color-Based Plot Style Table

Property

Value

Purpose

Maps colors to plot properties (lineweight, screening)

Format

Binary

Created By

AutoCAD Plot Style Manager

Used By

AutoCAD plotting

Found In

v7.0

Deprecation Status (2026): Active — still used in AutoCAD

Security — Windows XP: User-accessible in profile folder

Security — Windows 11 (2026): Same; stored in %AppData%\Autodesk

Compatibility: Forward-compatible; older CTB files work in newer AutoCAD

.CUI

AutoCAD Customization User Interface

Property

Value

Purpose

XML-based menu/toolbar customization (AutoCAD 2006+)

Format

XML

Language

XML

Created By

AutoCAD CUI Editor

Used By

AutoCAD 2006+

Found In

v7.0 (csv.cui)

Deprecation Status (2026): Active — replaced MNU/MNS in AutoCAD 2006+

Security — Windows XP: XML parsed directly; macro execution risks

Security — Windows 11 (2026): Same concerns; AutoCAD validates macros

Compatibility:

  • CUI replaced MNU format in AutoCAD 2006

  • v7.0 includes both MNU (legacy) and CUI (modern)

  • CUI files forward-compatible with newer AutoCAD

.DAT

Data File

Property

Value

Purpose

Generic data storage

Format

Application-specific

Created By

Various applications

Used By

Application that created it

Found In

v3.60

Deprecation Status (2026): Active — generic extension

Security: Application-dependent

Compatibility: Requires original application

.DCL

Dialog Control Language

Property

Value

Purpose

AutoCAD dialog box definition

Format

Text (DCL syntax)

Language

DCL (AutoLISP companion)

Created By

Text editor

Used By

AutoCAD via (load_dialog)

Found In

v3.60, v7.0 (80+ files)

Deprecation Status (2026): Legacy — superseded by:

  • ObjectARX dialogs (MFC/WinForms)

  • .NET dialogs (WPF)

  • AutoCAD Palette API

  • Web-based panels (2020+)

Security — Windows XP: Text file; no execution until loaded by AutoLISP

Security — Windows 11 (2026): Same; benign text format

Compatibility:

  • Still functional in AutoCAD 2026

  • Limited to basic controls (no modern UI widgets)

  • Appearance dated (Windows 3.1-era aesthetics)

  • Consider migration to .NET or web panels for new development

Example:

wall_dlg : dialog {
    label = "Wall Parameters";
    : edit_box { key = "thickness"; label = "Thickness:"; }
    ok_cancel;
}

.DCR

Shockwave Director File

Property

Value

Purpose

Macromedia Director compressed movie

Format

Binary (Director)

Created By

Macromedia Director

Used By

Shockwave Player

Found In

v3.60

Deprecation Status (2026): Obsolete — Shockwave discontinued 2019

Security — Windows XP: Required Shockwave plugin; significant attack surface

Security — Windows 11 (2026): Non-functional — no player available

Compatibility: None — requires legacy VM or Director source to convert

.DEFAULT

Default Configuration File

Property

Value

Purpose

Template/default settings

Format

Varies (typically text)

Found In

v3.60

Deprecation Status (2026): Pattern still used

Compatibility: Application-specific

.DLL

Dynamic Link Library

Property

Value

Purpose

Shared code library for Windows

Format

Windows PE (Portable Executable)

Language

C, C++, Delphi, etc.

Created By

Visual Studio, Delphi, etc.

Used By

Windows applications

Found In

v3.60, v7.0

Deprecation Status (2026): Active — core Windows technology

Security — Windows XP:

  • No mandatory code signing

  • DLL search order hijacking common

  • No ASLR/DEP enforcement

  • Side-by-side assemblies introduced (XP SP2)

Security — Windows 11 (2026):

  • Code signing expected (SmartScreen)

  • ASLR mandatory for system DLLs

  • DEP enforced

  • DLL search order hardened

  • Defender scans on load

Compatibility:

  • 32-bit DLLs won’t load in 64-bit processes

  • C runtime dependencies may be missing (MSVCRT versions)

  • Side-by-side manifests may be required

  • v3.60 DLLs likely require Visual C++ 6.0 runtime

.DWG

AutoCAD Drawing

Property

Value

Purpose

Primary AutoCAD drawing format

Format

Binary (proprietary, versioned)

Created By

AutoCAD, compatible CAD software

Used By

AutoCAD, DWG viewers, CAD applications

Found In

v3.60, v7.0

Deprecation Status (2026): Active — industry standard CAD format

Security — Windows XP: Binary format; historically targeted by malware

Security — Windows 11 (2026):

  • AutoCAD validates format

  • Can contain malicious scripts (AutoLISP in pre-2000 format)

  • TrustedDWG verification available

Compatibility:

  • DWG format versioned by AutoCAD release

  • Newer AutoCAD reads older DWG

  • Older AutoCAD cannot read newer DWG (requires save-down)

  • Open Design Alliance provides open-source libraries

.DWL

AutoCAD Drawing Lock File

Property

Value

Purpose

Prevents concurrent editing of DWG

Format

Text (username, machine name)

Created By

AutoCAD when opening DWG

Used By

AutoCAD to detect locks

Found In

v3.60

Deprecation Status (2026): Active — still created by AutoCAD

Security: Contains username/machine — minor information disclosure

Compatibility: Deleted when DWG closed; orphaned locks require manual removal

.EX_

Compressed Executable

Property

Value

Purpose

COMPRESS.EXE compressed executable

Format

MS-DOS COMPRESS format

Created By

COMPRESS.EXE (MS-DOS/Windows)

Used By

EXPAND.EXE to decompress

Found In

v3.60 (_INST32I.EX_)

Deprecation Status (2026): Obsolete — replaced by CAB, ZIP, MSI

Security — Windows XP: Required expansion before execution

Security — Windows 11 (2026): expand.exe still available

Compatibility: Use expand _INST32I.EX_ _INST32I.EXE to decompress

.EXE

Windows Executable

Property

Value

Purpose

Windows application or installer

Format

Windows PE (Portable Executable)

Language

Various (C, C++, Delphi, VB, .NET)

Created By

Compilers, linkers

Used By

Windows

Found In

v3.60, v7.0

Deprecation Status (2026): Active — primary Windows executable format

Security — Windows XP:

  • No code signing required

  • Run as invoking user (often Administrator)

  • No UAC prompts

  • DEP opt-in only

Security — Windows 11 (2026):

  • SmartScreen blocks unsigned/unknown

  • UAC prompts for admin operations

  • ASLR/DEP mandatory

  • Defender real-time scanning

  • Virtualization-based security (VBS) on supported hardware

Compatibility:

  • 16-bit EXE (Win3.x): Not supported on 64-bit Windows

  • 32-bit EXE: Runs via WoW64 subsystem

  • Dependencies (DLLs, runtimes) may be missing

  • Manifest required for DPI awareness, UAC level

.FAS

AutoLISP Compiled File

Property

Value

Purpose

Compiled/encrypted AutoLISP bytecode

Format

Binary (AutoLISP bytecode)

Language

Compiled AutoLISP

Created By

AutoCAD (vlisp-compile)

Used By

AutoCAD LISP engine

Found In

v3.60 (109 modules in VLX), v7.0

Deprecation Status (2026): Active — still supported for code protection

Security — Windows XP: Bytecode not human-readable; provides IP protection

Security — Windows 11 (2026): Same; bytecode format unchanged

Compatibility:

  • FAS files are version-independent (unlike ARX)

  • FAS from AutoCAD 2000 works in AutoCAD 2026

  • Cannot be decompiled (protection measure)

  • Source required for modifications

.GID

Windows Help Global Index

Property

Value

Purpose

Full-text search index for .HLP files

Format

Binary index

Created By

WinHelp when user searches

Used By

WinHelp search

Found In

v3.60

Deprecation Status (2026): Obsolete — WinHelp removed from Windows 10+

Security — Windows XP: Generated locally; no concerns

Security — Windows 11 (2026): WinHelp not available without third-party tools

Compatibility: Requires WinHlp32.exe installation (unsupported)

.HDR

InstallShield Header File

Property

Value

Purpose

CAB header/metadata for InstallShield

Format

Binary

Created By

InstallShield compiler

Used By

InstallShield runtime

Found In

v3.60 (_sys1.hdr, _user1.hdr, data1.hdr)

Deprecation Status (2026): Deprecated — specific to InstallShield 5.x/6.x

Security: Metadata only; installer security applies

Compatibility: Requires matching CAB files; use Unshield to extract

.HLP

Windows Help File

Property

Value

Purpose

Application help documentation

Format

Binary (WinHelp 4.0)

Created By

Help Workshop (HCW.EXE)

Used By

WinHelp (WINHLP32.EXE)

Found In

v3.60, v7.0 (CSV.Hlp)

Deprecation Status (2026): Obsolete — WinHelp removed from Windows

Security — Windows XP:

  • Could contain embedded macros

  • Some help files executed code

  • Security vulnerabilities led to deprecation

Security — Windows 11 (2026):

  • WinHelp not included

  • Microsoft provides unsupported download for Windows 8.1 and earlier

  • No official support for Windows 10/11

Compatibility:

  • Convert to CHM (HTML Help) or web-based help

  • Third-party HLP viewers exist

  • Content extraction tools available

.INF

Setup Information File

Property

Value

Purpose

Driver installation, setup configuration

Format

Text (INI-style sections)

Created By

Text editor, setup tools

Used By

Windows Setup, device installation

Found In

v3.60

Deprecation Status (2026): Active — still used for driver installation

Security — Windows XP: Right-click “Install” ran arbitrary commands

Security — Windows 11 (2026):

  • UAC required for installation

  • Driver signing required for kernel drivers

  • Defender scans referenced files

Compatibility: INF format stable; syntax well-documented

.INI

Initialization File

Property

Value

Purpose

Application configuration

Format

Text (key=value sections)

Created By

Applications, text editor

Used By

Applications via GetPrivateProfileString API

Found In

v3.60 (SETUP.INI)

Deprecation Status (2026): Legacy — replaced by Registry, XML, JSON

Security — Windows XP: Plain text; editable by users

Security — Windows 11 (2026): Same; INI in Program Files requires elevation

Compatibility:

  • Windows API still supports INI files

  • Modern apps prefer %AppData% location

  • Consider migration to JSON/XML for new development

.INS

InstallShield Script (Compiled)

Property

Value

Purpose

Compiled InstallShield installation script

Format

Binary (InstallScript bytecode)

Language

InstallScript (C-like)

Created By

InstallShield IDE

Used By

InstallShield runtime

Found In

v3.60 (setup.ins)

Deprecation Status (2026): Deprecated — InstallShield evolved significantly

Security — Windows XP: Full installer privileges; ran as admin by default

Security — Windows 11 (2026): Would require admin elevation; likely blocked by Defender

Compatibility:

  • Requires matching InstallShield runtime

  • v3.60 uses InstallShield 5.x format

  • Cannot decompile; string extraction only

.JPG / .JPEG

JPEG Image

Property

Value

Purpose

Compressed raster image

Format

JPEG/JFIF

Created By

Cameras, image editors

Used By

Universal

Found In

v7.0

Deprecation Status (2026): Active — ubiquitous image format

Security — Windows XP: Early parsers had buffer overflow vulnerabilities

Security — Windows 11 (2026): Hardened parsers; safe

Compatibility: Universal

.LID

InstallShield Language ID File

Property

Value

Purpose

Localization metadata for installer

Format

Binary/text

Created By

InstallShield

Used By

InstallShield runtime

Found In

v3.60 (setup.lid)

Deprecation Status (2026): Deprecated — InstallShield format evolved

Compatibility: Legacy InstallShield only

.LNK

Windows Shortcut

Property

Value

Purpose

Link to file, folder, or URL

Format

Binary (Shell Link)

Created By

Windows Explorer, applications

Used By

Windows Shell

Found In

v3.60, v7.0

Deprecation Status (2026): Active — core Windows feature

Security — Windows XP:

  • Could point to malicious targets

  • Icon extraction vulnerabilities existed

  • Autorun exploits via LNK

Security — Windows 11 (2026):

  • Same potential for misdirection

  • Icon handler hardened

  • Defender inspects targets

Compatibility: Forward/backward compatible

.LSP

AutoLISP Source File

Property

Value

Purpose

AutoCAD automation scripts

Format

Text (LISP syntax)

Language

AutoLISP (LISP dialect)

Created By

Text editor, Visual LISP IDE

Used By

AutoCAD via (load)

Found In

v3.60, v7.0 (100+ files)

Deprecation Status (2026): Active — still primary AutoCAD scripting

Security — Windows XP:

  • No execution restrictions

  • Could modify files, registry, run programs

  • ACAD.LSP auto-execution vulnerability

Security — Windows 11 (2026):

  • AutoCAD SECURELOAD setting controls loading

  • Trusted paths concept

  • Still powerful — can call Windows API via (vlax-*) functions

Compatibility:

  • AutoLISP syntax stable since 1980s

  • Visual LISP extensions (vl-, vlax-) added in AutoCAD 2000

  • ActiveX automation deprecated in favor of .NET

  • Legacy code generally runs unmodified

Example:

(defun c:HELLO ()
  (alert "Hello from ConstructiVision!")
)

.MKP

AutoCAD Migration Markup

Property

Value

Purpose

Settings migration between AutoCAD versions

Format

XML

Created By

AutoCAD migration utility

Used By

AutoCAD setup

Found In

v7.0

Deprecation Status (2026): Active — still used for profile migration

Compatibility: Version-specific; generated during upgrades

.MNC

AutoCAD Compiled Menu

Property

Value

Purpose

Compiled menu file (faster loading)

Format

Binary

Created By

AutoCAD from MNU/MNS

Used By

AutoCAD menu system

Found In

v3.60, v7.0

Deprecation Status (2026): Legacy — CUI/CUIX replaced MNC in AutoCAD 2006+

Security: Compiled version of menu; contains macros

Compatibility:

  • AutoCAD 2006+ prefers CUI format

  • MNC still loadable for backward compatibility

  • Delete MNC to force recompile from MNS

.MNR

AutoCAD Menu Resource

Property

Value

Purpose

Menu bitmaps and resources

Format

Binary (resource file)

Created By

AutoCAD from MNU

Used By

AutoCAD menu rendering

Found In

v3.60, v7.0

Deprecation Status (2026): Legacy — resources now in CUI/CUIX

Compatibility: Used alongside MNC for legacy menus

.MNS

AutoCAD Menu Source

Property

Value

Purpose

Text version of menu (user-editable)

Format

Text

Created By

AutoCAD (from MNU), text editor

Used By

AutoCAD (compiles to MNC)

Found In

v3.60, v7.0

Deprecation Status (2026): Legacy — editable but CUI preferred

Security: Text file; contains macro definitions

Compatibility: Can be loaded in AutoCAD 2006+; converted to partial CUI

.MNU

AutoCAD Menu Definition

Property

Value

Purpose

Original menu definition file

Format

Text (section-based)

Created By

Text editor

Used By

AutoCAD (pre-2006)

Found In

v3.60, v7.0 (csv.mnu)

Deprecation Status (2026): Legacy — CUI replaced MNU in AutoCAD 2006

Security — Windows XP: Macros could execute system commands

Security — Windows 11 (2026): Same concerns; AutoCAD validates on load

Compatibility:

  • AutoCAD 2006+ migrates MNU to CUI on first load

  • Keep MNU for backward compatibility with older AutoCAD

  • Migration may require manual adjustment

Example:

***MENUGROUP=CSV
***POP1
[ConstructiVision]
[Panel]^C^C^P(load "panel")^P
[Wall]^C^C^P(load "wall")^P

.PDF

Portable Document Format

Property

Value

Purpose

Document distribution

Format

PDF (Adobe)

Created By

Various applications

Used By

PDF readers, browsers

Found In

v7.0

Deprecation Status (2026): Active — industry standard document format

Security — Windows XP: JavaScript in PDFs was attack vector

Security — Windows 11 (2026):

  • Protected View in readers

  • JavaScript execution restricted

  • Edge displays PDFs natively

Compatibility: Universal

.PNL

AutoCAD Tool Palette Panel

Property

Value

Purpose

Tool palette definition

Format

XML

Created By

AutoCAD palette customization

Used By

AutoCAD tool palettes

Found In

v7.0

Deprecation Status (2026): Active — tool palettes still used

Compatibility: Version-specific; may require migration

.PRJ / .PRV

ConstructiVision Project Files

Property

Value

Purpose

Project configuration and variables

Format

Text (AutoLISP-readable)

Created By

ConstructiVision

Used By

ConstructiVision

Found In

v3.60, v7.0

Deprecation Status (2026): Application-specific legacy format

Security: Plain text; editable

Compatibility: ConstructiVision-specific; documented in project toolchain notes

.REG

Registry File

Property

Value

Purpose

Registry export/import

Format

Text (REGEDIT format) or Binary (CREG)

Created By

REGEDIT, installers

Used By

REGEDIT, Windows

Found In

v3.60 (WINCSS.REG — binary CREG format)

Deprecation Status (2026): Active — standard Windows format

Security — Windows XP:

  • Double-click merged into registry

  • No confirmation prompts in some versions

  • Could modify any registry key with permissions

Security — Windows 11 (2026):

  • UAC required for HKLM writes

  • Confirmation dialog shown

  • Defender may scan for malicious entries

Compatibility:

  • Text REG files (REGEDIT4, REGEDIT5) are universal

  • Binary CREG format (InstallShield) requires special handling

Note: v3.60’s WINCSS.REG is not standard .REG — it’s InstallShield CREG binary format.

.RUL

InstallShield Rules File

Property

Value

Purpose

InstallScript source code

Format

Text (C-like syntax)

Language

InstallScript

Created By

InstallShield IDE, text editor

Used By

InstallShield compiler

Found In

v3.60

Deprecation Status (2026): Active (in InstallShield) but format evolved

Security: Source code; compiled to INS

Compatibility: InstallShield version-specific

.SCR

AutoCAD Script File

Property

Value

Purpose

AutoCAD command automation

Format

Text (command sequence)

Created By

Text editor

Used By

AutoCAD via SCRIPT command

Found In

v3.60, v7.0

Deprecation Status (2026): Active — still used for batch operations

Security — Windows XP: Could execute any AutoCAD command

Security — Windows 11 (2026): Same; scripts can call LISP routines

Compatibility: Universal AutoCAD format; syntax unchanged

Note: .SCR also used for Windows screensavers — different format!

.SHX

AutoCAD Shape/Font File

Property

Value

Purpose

Vector fonts and shapes

Format

Compiled shape definition

Created By

AutoCAD COMPILE command from .SHP

Used By

AutoCAD text and shapes

Found In

v3.60, v7.0

Deprecation Status (2026): Active — still primary AutoCAD font format

Security — Windows XP: Binary format; minimal risk

Security — Windows 11 (2026): Same; validated by AutoCAD

Compatibility:

  • SHX fonts work across AutoCAD versions

  • Missing fonts substitute with alternatives

  • TrueType fonts (.TTF) also supported

.TAG

InstallShield Data Tag

Property

Value

Purpose

InstallShield installation metadata

Format

Text

Created By

InstallShield

Used By

InstallShield runtime

Found In

v3.60 (DATA.TAG)

Deprecation Status (2026): Deprecated — InstallShield format evolved

Compatibility: Legacy InstallShield only

.TXT

Text File

Property

Value

Purpose

Plain text documentation

Format

Plain text

Created By

Any text editor

Used By

Universal

Found In

v3.60, v7.0 (Readme.txt, License.txt)

Deprecation Status (2026): Active — universal format

Security: Plain text; safe

Compatibility: Universal

.VLX

Visual LISP Executable

Property

Value

Purpose

Packaged AutoLISP application

Format

Binary container (FAS + DCL + resources)

Created By

Visual LISP IDE (vlisp-make-exe)

Used By

AutoCAD via (vl-load-com), (load)

Found In

v3.60, v7.0 (CSV.VLX)

Deprecation Status (2026): Active — still supported and used

Security — Windows XP: Protected distribution format; code encrypted

Security — Windows 11 (2026): Same; provides IP protection

Compatibility:

  • VLX format version-independent

  • v3.60 VLX (109 FAS modules) works in AutoCAD 2026

  • v7.0 VLX (1 FAS module) also compatible

  • Cannot modify without source code

Structure:

CSV.VLX
├── CSV.FAS (compiled entry point)
├── MODULE1.FAS
├── MODULE2.FAS
├── ...
├── DIALOG1.DCL
└── DIALOG2.DCL

.XDV

AutoCAD External Database View

Property

Value

Purpose

Database connectivity configuration

Format

XML

Created By

AutoCAD dbConnect

Used By

AutoCAD database features

Found In

v7.0

Deprecation Status (2026): Legacy — database connectivity evolved

Compatibility: AutoCAD version-specific

.ZIP

ZIP Archive

Property

Value

Purpose

Compressed file archive

Format

ZIP (PKZIP compatible)

Created By

WinZip, 7-Zip, Windows Explorer

Used By

Universal

Found In

v7.0 (WF.zip)

Deprecation Status (2026): Active — universal compression format

Security — Windows XP:

  • Extracted files ran with full permissions

  • No built-in scanning

Security — Windows 11 (2026):

  • Windows extracts natively

  • Defender scans contents

  • Mark-of-the-Web applied to extracted files

Compatibility: Universal

Summary Tables

By Status (2026)

Status

Extensions

Active

.ARX, .BAK, .BMP, .CAB, .CTB, .CUI, .DCL, .DLL, .DWG, .EXE, .FAS, .INF, .JPG, .LNK, .LSP, .PDF, .PNL, .REG, .SCR, .SHX, .TXT, .VLX, .ZIP

Legacy

.AC$, .BHF, .BIN, .DAT, .HDR, .INI, .MNC, .MNR, .MNS, .MNU, .PRJ, .PRV, .RUL, .XDV

Deprecated

.CIF, .INS, .LID, .TAG

Obsolete

.DCR, .EX_, .GID, .HLP

By Security Risk

Risk Level

Extensions

High

.ARX, .DLL, .EXE, .INS (code execution)

Medium

.LSP, .MNU, .SCR, .REG (script/registry)

Low

.DCL, .INI, .TXT, .BMP (data/config)

Status: Complete | Updated: 2026-01-20