[PayneTrain]

As an additional detail, FIRST used to assign temporary numbers until in 1997 (or 1998?) all existing and incoming teams were assigned permanent numbers, with numbers grouped by alphabetical order of the primary sponsorship. That is why 116, 118, and 122 are grouped together (NASA) 45, 47, and 48 are grouped together (Delphi) and a founding and sustaining team has number 190 (WPI)

The significance of permanent numbers means that if a team folds, the number is never reissued. If a team takes gap years, the number is never reissued (Team 23 has been in and out of FIRST for the last two decades).

FIRST's policy now is that numbers are held by what I believe they deem the sponsoring organization, the 501c3 or school/school system that the number was issued to. If memory serves me right, when 1771 lost teacher support in 2012, the mentors and sponsors did not take the number over to a different school, but were instead issued a new number.

If a sponsoring organization does not sponsor a team for a period of 3 years (I think it's 3) the sponsoring organization has the option to apply for a rookie number. This means the organization forgoes team history and gets a fresh start, including the ability to apply for rookie grants and awards. 5546 out of Petersburg, VA is the new team that started this year, a decade after the old team 404 folded.

There is other information regarding splits and merges that aren't relevant to your situation, but FIRST covers most every aspect of number assignment.