Direct Answer
'Approved as Noted' (A/N) means the engineer reviewed the drawings and found them acceptable provided that specific written corrections are made. The fabricator should not start production until the detailer has incorporated all notes and confirmed with the engineer, or until the GC has explicitly authorized limited fabrication on specific sheets at your risk.
Full Explanation
A/N comments range from minor clarifications (add a note about weld access) to substantive revisions (change bolt group from 4-bolt to 6-bolt pattern). The detailer must resolve each note, revise the drawings, and reissue. If the comment is truly minor and the engineer explicitly authorizes fabrication to proceed while revisions are processed, get that authorization in writing. Never infer authorization from silence.
What This Means for Your Shop
A/N is the most dangerous approval status because fabricators sometimes treat it as an informal 'go ahead.' It is not. Fabricating from unresolved A/N drawings is how fabricators absorb rework costs that should have been the engineer's responsibility.
Common Mistakes
Assuming that because 90% of a drawing set is approved, the A/N sheets are fine to run. Each A/N comment must be resolved individually. Also: losing track of which comments have been resolved on re-submitted drawings.
Recommended Process
When drawings are returned A/N, forward immediately to the detailer with a resolution deadline. Request that the detailer summarize how each comment was addressed in the re-submittal cover letter. Track in your submittal log until formal approval is received.