What year did the NFL start enforcing specific numbering protocols for Jerseys?

You know....WRs and TEs in the 80s, Kickers and QBs below 20, no 00 anymore....





And what exactly are the current number ranges?What year did the NFL start enforcing specific numbering protocols for Jerseys?
1973


based on primary positions


1-19 qb's, k, p


Numbers 20 to 49 are worn by running backs, tight ends (between 40-49 when an 80-89 number is unavailable), cornerbacks and safeties.


Numbers 50 to 59 are worn by linebackers and offensive linemen.


Numbers 60 to 79 are worn by members of both the offensive line (the tackles, guards and centers) and defensive line (the defensive ends, defensive tackles or nose guard).


Numbers 80 to 89 are worn by wide receivers and tight ends.


Numbers 90 to 99 are worn by linebackers and defensive linemen.


Numbers 0 and 00 are no longer usedWhat year did the NFL start enforcing specific numbering protocols for Jerseys?
why does the NFL fine players if their socks arent tucked properly into their pants? The NFL is obsessed with uniformity
73
in the late 70's I belive %26lt;%26lt;%26gt;%26gt;WR's can now wear #'s in the teens
Just to add on to what Jason has mentioned, numbers 11-19 are now used by wide receivers, in cases in which the 80s are unavailable.