why the designator of ASME clause is not continuous?

[YuJie_PV]

i have a question about ASME history.
as i read ASME VIII-1, i find the clause No. is not continuous. for example, UG-1 is scope, and the next clause is UG-4 on material general.
i guess UG-2&3 may be deleted during the development of ASME, is it true?
any knowledgeable expert knows the history of ASME？

 

[Geoff13]

I only have Codes back to 2001, and it is the same.

 

[EdStainless]

It is the same reason that the material specification numbers are not continuous.
They are assigned sequentially and numbers are never reused.
As old ones are retired (usually built into the code) they are just eliminated.
Once upon a time they kept them all in a list and told you what happened.
But back then the entire Code was in one volume.

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