Vn-uni.shx is a specialized AutoCAD "Shape" font designed to support the Vietnamese language Tai Font Vn-uni.shx

Step 1: The Quick Fix – Font Substitution (Temporary)

Part 6: A Cultural Note – The Vietnamese Typing Landscape

• Tai : This most likely refers to Tahoma, a popular sans-serif font designed by Matthew Carter for Microsoft. In the late 1990s and early 2000s, Tahoma was widely adopted for on-screen interfaces due to its clarity. The "Tai" prefix suggests this SHX file is a derivative or a specialized clone of Tahoma’s metrics, adapted for the single-line stroke style of AutoCAD.
• Font : Clearly indicates this is a typography resource.
• Vn : The abbreviation for Vietnam. This is the critical clue. The file was specifically created to handle Vietnamese diacritics (accents, tone marks, and the distinctive đ character).
• Uni : Stands for Unicode. This points to a major evolution. Prior to Unicode, Vietnamese fonts used proprietary encoding systems (like VNI or TCVN3/ABC). A "Uni" label implies the font maps characters according to the international Unicode standard, allowing for cross-platform compatibility.
• .shx : This is the proprietary file extension for AutoCAD Compiled Shape File. Unlike standard Windows TrueType fonts (.ttf), SHX fonts are made of simple, single-line strokes. They are lightweight, render very quickly, and are ideal for vectors and CAD plots.

If you are trying to develop or modify the font itself, you cannot edit the .shx file directly because it is a compiled binary. Tai Font Vn-uni

Technical Overview: Vn-uni.shx and Vietnamese Font Integration in AutoCAD Vn-uni