What does the command documentation actually say?
Autodesk's AutoCAD 2027 command reference states that ATTSYNC applies attribute changes in a block definition to references while preserving assigned attribute values. It also warns about removal of formatting or property edits, extended data and possible effects on dynamic or third-party blocks.
DWG Conversion is independent and is not affiliated with Autodesk. Do not treat the command as a safe bulk correction of drawing identity. Test an authorized working copy and retain the received native file before any migration action.
Sources: Autodesk: ATTSYNC command, AutoCAD 2027 documentation
Which layers of information need separate checks?
A migrated block can have the expected attribute tag and appearance while retaining an old project value. Compare actual inserted values against the approved drawing register. Do not automatically apply a template's sample identity to every sheet.
| Field | Evidence | Review action |
|---|---|---|
| Definition | Attribute tag, prompt, default and intended properties | Compare with the approved target template |
| Existing reference | Actual assigned value on the sheet | Compare with that drawing's approved identity |
| Appearance | Position, visibility, style and formatting | Inspect native and plotted output |
| Additional data | Dependencies on extended or third-party data | Test with the responsible file owner |
| Release | Reviewed values and plot for each affected sheet | Retain a discrepancy and change record |
How can the right template leave the wrong revision?
Illustrative example. A fictional title block has an existing REV attribute value A. The target definition uses B as its default. A synchronisation of the existing attribute definition does not establish that the inserted value became B. Inspect the actual sheet value and compare it with the approved revision record.
If the approved revision is A, replacing it merely because the template default is B would introduce an error. If the approved revision is B, update the actual value through the authorized editing workflow and verify the resulting native and PDF outputs. The example is about evidence, not a blanket instruction to change revision labels.
What makes the migration ready to issue?
Review all affected sheet identities and any deliberately different values, not only one sample title block. Keep definition changes, value changes and formatting changes distinguishable in the log. Report unresolved fields rather than fill them from a neighbouring sheet.
Engineering content and its revision authority remain with the responsible project reviewers. Engineering sign-off is performed only by the registered engineer on the job.
Common questions
What else should the bid team know?
Does a new default prove existing values changed?
No. Inspect the values assigned to the actual block references.
Can synchronisation affect formatting or extra data?
The Autodesk command reference warns about these effects. Test an authorized copy first.
Should every sheet receive the same revision value?
Only where the approved drawing register requires it. A template default is not revision authority.