Board Thread:Wikia Discussion/@comment-141749-20170525045750/@comment-1017333-20170526233447

PE (for Patrol/Escort)

Kaiboukan are clearly Patrol ships of some kind, for which the US desgination is P. I initially selected E since I wanted to include escort for clarity. However, the US actually built a class of PE. (You can find the full list of US patrol types here .) While slightly smaller, the growth seems in line with the growth in size of all types during the period in question.