... depends!
The main factor regarding SIC lies with the certification of the Citation. There are a bunch of Citations out there, and some may look identical, but beware! A CE-500 is not a CE-501! Some Citations are certified under CFR 25 (transport category) and others under CFR 23 (GA). I really don't know who accepts SIC in a CFR 23 Citation or not. I went to a regional-airline interview earlier this year and they questioned me about some SIC CE-501 135 time like I was some kind of retard.
Also: The FAA allows you to fly a multi-pilot Citation (CFR 25) single-pilot with a letter of authorization.
I was told by Flight Safety that you cannot log SIC in a CJ (CitationJet). This is a completely different type rating than the regular Citations and your type rating here in the US says CE-525S (s for single pilot only).
Please bear in mind that all this refers to the FAA regs. I am out of the loop with the JAA regs.
Hope this helps.
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