APH is an abbreviation of the anime series Hetalia: Axis Powers. Used informally as a short form to the full title since pixiv does not allow 2 or more words with space grouped as one tag (with the exception of using underscore).
In pixiv, this abbreviation is not really used due to the following reasons :
- For casuals who doesn't know much about the series, it is very unlikely for them to know about APH, and easier to get results by typing "ヘタリア" (Hetalia) in.
- Since the portmanteau of Hetalia is only used frequently at NicoNicoDouga and 2ch, it is not necessary to list them seperately.
- While APH can be used to hide any works related to Hetalia, it is considered to be pointless and effort wasting due to being easily identifiable.
Hetalia: Axis Powers