Criteria for competing for promotion during a centralized promotion board is covered by AR 600-8-19, Chapter 5, Section III. Detailed qualifications/disqualifications for a specific board i.e. the SFC Promotion Board is released with the publication of the MILPER Message that announces the board.
Paragraph 5-32 of the regulation states:
A Soldier with a FLAG in effect may be considered by the board and placed on the recommended list. However, the Soldier cannot be promoted until the FLAG has been lifted (nonwaivable).
Furthermore, Paragraph 5-37c(1) states:
The names of Soldiers recommended for promotion who are under suspension of favorable personnel action (AR 600–8–2) will be placed on the selection list and monitored until the action is completed. These Soldiers cannot bepromoted until the suspension (FLAG) has been lifted (see para 1–11, of this regulation).