Standard Alphabetic Scheme
When using the standard alphabetic scheme, version identifiers are first assigned as a single letter. After all letters from A through Z have been assigned, the following series are used:
AA-ZZ
• AA, AB, AC, ..., AZ
• BA, BB, BC, ..., BZ
• (and so on)
AAA-ZZZ
• AAB, AAC, ..., AAZ
• BAA, BAB, BAC, ..., BAZ
• (and so on)