This fixes a problem with retail, seen most prominently in FSPort, where the game will complain if the player is assigned a #weak weapon that isn't player allowed. Retail FS1 had the player-allowed flag on the Interceptor but not on the Interceptor#Weak.
Right now, the code just checks for the five characters #-w-e-a-k but doesn't check any characters after that. The solution would be to check that the string ends after #weak.
On the other hand, the latest version of FSPort assigns player-allowed to Interceptor#weak, so maybe we should just remove the fix entirely.