Collection, or kitchen?

[Philip]

Originally Posted by Ren Ren

These marks are similar to Vietnamese letters "HĐ" and "fi".

The romanized Vietnamese alphabet has no F. The combined letters PH are its phonetic equivalent in the written language.

(Just for additional information, there is no W either. OA is substituted, for instance oanh is pronounced something like wan.)

[Ren Ren]

You are absolutely right, Philip! Thanks for these important comments!