A dimension that has been typed over no longer reports the geometry it measures. That is the single most dangerous thing that can be left in a drawing before it goes out, because it looks correct and reads correct while being a hand-typed lie. DIMTATTLE finds every one and recolours it red.
What DimTattle does
It is a pre-issue check, and it takes one command. Every dimension whose measured value has been replaced with typed text turns red so it cannot be missed.
The recolour is a real edit and lands in its own undo group, so a single U immediately afterwards puts the drawing back the way it was.
How to use it
- Load the routine with
APPLOAD, or put it on your support file search path. - Type
DIMTATTLEbefore issuing a drawing. - Check every red dimension. Either restore the measured value or confirm the override is deliberate and correct.
- Undo to put the colours back.
How it works
DXF group 1 on a dimension holds the text override, and its three possible states are what the check turns on:
“” — no override. The dimension reports its measured value.“*<>*” — the measured value is still present, shown by the <> token, with a prefix or suffix added around it, such as <>mm. This is legitimate annotation, not a lie, so it is ignored.
Anything else — the measured value has been replaced outright. This is what gets flagged.
The selection filter therefore picks dimensions that are not empty and do not contain <>. That distinction is the whole routine: a dimension reading <> TYP is annotated, while one reading 2400 where the geometry says 2380 is a defect, and telling them apart is what makes the check worth running.
Notes and limits
- Prefixes and suffixes are not flagged. Anything containing
<>still reports the real measurement, so it is left alone. - A red dimension is not necessarily wrong — it is one that needs a human to confirm. Some overrides are deliberate.
- The recolour is an edit. One undo reverses it; do not issue the drawing with the check still applied.
- Run it alongside DIMCLASH for the two dimension faults that survive to the printed sheet.
Download and details
| Name | DimTattle — highlight dimensions whose text has been manually overridden |
| Download | DimTattle.lsp — 4.4 KB, plain AutoLISP source. Downloads directly; no zip to unpack. |
| Type | AutoCAD AutoLISP routine |
| Command | DIMTATTLE |
| Requires | nothing beyond a CAD platform with AutoLISP. |
| Source size | 4.4 KB, 114 lines |
| Error handling | Yes — a *error* handler restores every system variable it changed, on cancel as well as on error. |
| Undo | The whole operation is wrapped in a single undo group, so one U reverses all of it. |
| Compatibility | AutoCAD (any release with AutoLISP), BricsCAD, ZWCAD, GstarCAD, ProgeCAD and other IntelliCAD-based platforms. AutoCAD LT needs a LISP enabler. No .NET, no ObjectARX, no installer. |
| Author | YZ, August 2026 |
| Licence | Free to use, supplied “as is” with no warranty. |
References
- DIMCLASH LISP — the other pre-issue check: dimensions overlapping each other
- What NTS means — when a drawing may legitimately not be to scale
- More free AutoLISP routines on this site
- Wisey’s Steel Shapes — free structural steel section drawing program