More or less as the title. I'm helping transcribe some games for a team tournament that is happening, but I can't find any field in the software I'm using or even the PGN format specification for a 'Team' field. Considering that this problem must have occurred before for high-profile team events (Olympiad, Bundesliga, etc.), is there an accepted way to record this information in a PGN file?
There are two fields I have seen used extensively for this purpose: WhiteTeam and BlackTeam.
They don't appear to be documented in the PGN Standard, but don't let that discourage you.
As one example, I have found these fields present in the Olympiad 2016 Baku PGN games download file. They are also present in any PGN file created from a MegaBase database for a team tournament. They are also included in every PGN file published by The Week In Chess (TWIC) by Mark Crowther and by ChessBase Magazine, such as the World Team Championships, the French, Swedish and Hungarian Team Championships, the United States Chess League, the European Club Cup, and so on.
This means they are populated by publishers of game scores, and also that they are stored in a CBH-format database. The PGN handler for ChessBase will both export and import these fields within the PGN data.