I am a mechanical design working daily with Autodesk Inventor in a precision manufacturing environment. The uses of Limited Dimension Drawing (LDD) methodology with general profile tolerances per ASME Y14.5 / ISO GPS, which requires Datum Identifier Symbols (A, B, C) to be placed on every single drawing produced.
A wide range of drawing annotations can already be created programmatically via iLogic/API:
Object Creatable via API?
| FeatureControlFrame (GD&T) |  Yes |
| SurfaceTextureSymbol |  Yes |
| Balloon, DrawingNote, Dimension |  Yes |
| DatumIdentifierSymbol |  No — not exposed |
The DatumIdentifierSymbol is the only critical GD&T annotation that cannot be created programmatically, making it impossible to fully automate LDD/GD&T drawing workflows.
I have investigated every possible workaround — launching the native command, SendKeys, SketchedSymbol — and none are acceptable for a professional GD&T workflow. The API simply does not expose this object.
For engineers doing LDD/GD&T drawings all day, every day, this single missing piece breaks the entire automated pipeline and forces repetitive manual work on every drawing.
What the API needs:
- A DatumIdentifierSymbols collection on the Sheet object, analogous to FeatureControlFrames
- Ability to create stand-alone and leader-attached symbols programmatically
- Read/write access to identifier, position, style, and leader points
This is not a niche request. Any company using ASME or ISO GPS, LDD, or systematic GD&T with general profile tolerances hits this wall immediately. The FeatureControlFrame API already exists — DatumIdentifierSymbol is the natural and necessary complement.
Please prioritize this. It has been a gap in the API for years.
CAD Regards,
Pedro Monteiro
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