I came across this in the PGN standard on this site, section 17, for alternative piece identifiers (emphasis mine):
English language piece names are used to define the letter set for identifying chesspieces in PGN movetext. However, authors of programs which are used only for local presentation or scanning of chess move data may find it convenient to use piece letter codes common in their locales. This is not a problem as long as PGN data that resides in archival storage or that is exchanged among programs still uses the SAN (English) piece letter codes: "PNBRQK".
Followed by a table of symbols for different languages.
The first part seems to suggest that one can use identifiers from other languages to represent the pieces if one so wishes.
However, the highlighted part seems to contradict that, saying that, ultimately, the PGN should use the English identifiers and not those of any other language.
It appears that a mistake in my understanding caused this contradiction, so I'd be glad if someone could please clarify it.
Can one use symbols from languages other than English for representing pieces in a PGN file?
Would something like this work (using the piece identifiers in German)?
[Event "Casual game"] [Site "Hogwarts"] [Date "2018.03.09"] [Round "1"] [White "Malfoy, Draco"] [Black "Weasley, Ronald"] [Result "*"] [TimeControl "1/15+1"] [FEN " "] 1. e4 e5 2. Sf3 Sc6 3. Lb5 Sf6 4. O-O Sxe4 *