Reminder:

UniProtKB accession numbers currently consist of 6 alphanumerical characters. Due to the rapid growth of UniProtKB, we have been using up all accession numbers of this format and will therefore extend the format to 10 alphanumerical characters starting release 2014_06.

Read more here: http://www.uniprot.org/changes and contact the UniProt helpdesk with any comments you might have.

Note: Short and long versions will co-exist. New ACs are assigned to new entries, and already assigned ACs usually do not change. Merges and demerges will be handled like with the current AC scheme: http://www.uniprot.org/manual/accession_numbers.

Possible future AC/ID line pairs (fictitious):

ID   A0A023GPJ1_DROME        Unreviewed;       673 AA.
AC   A0A023GPJ1;

ID   A0A023GQU8_STAAU        Unreviewed;       358 AA.
AC   A0A023GQU8; A0A016JZJ0; Q9S446;

ID   Q9ZFS6_STAAU            Unreviewed;       166 AA.
AC   Q9ZFS6; A0A020FNV5;