Revisions missing in PLM

[PLM-Sylvain.Bailly]

Hello,

There is a reason why the following revision letters don't exist: I, O, Q, S, X and Z (see attachment for more fun).

Best regards,

Sylvain

[mpasumarti · Accepted solution]

According to ASME standards,

All letters can be used as revision letters except I, O, Q, S, X and Z. These letters are not allowed because they can be mistaken for numbers or for other letters. For example, a revision letter I can be mistaken for a 1 while an S can be mistaken for a 5. Revision letters must also be uppercase, to minimize confusion between a lowercase "l" and "1" and "I".

Read on the following article for additional information on this.

https://owlcation.com/humanities/ASME-Standards-for-the-Revision-of-Engineering-Drawings

There is a contrary to the above standard, read on the following post,

http://www.eng-tips.com/viewthread.cfm?qid=362599

[PLM-Sylvain.Bailly]

Thank you very much Madhav

I didn't know ASME standards. We mainly use the ISO norms and the equivalent for us is the ISO 7200:2004:

"5.1.4 Revision index

The revision index identifies the revision status of the document. Different versions are numbered in

consecutive order by means of, e.g. a letter or letter combination A to Z, then AA, AB, AC ... or Figures 1, 2,

3 ... The letters I and O should be avoided because they are easily confused with the digits 1 and 0."

[mpasumarti]

Good to know that.