The TimeControl formats I've found on the web split the TimeControl in time periods separated by a special character, for instance:
G/90 (one period with 90min to end the game)
G/90+30 (one period with 90min to end the game and 30sec of increment)
40/90, SD/30+30 (two periods, 90min to play 40 moves followed by 30 min to end the game with 30sec of increment)
Now, in the last example the increment is related to the second period (the sudden death).
According to http://www.fide.com/fide/handbook.html?id=39&view=category for all major FIDE events the TimeControl is 90 minutes for the first 40 moves followed by 30 minutes for the rest of the game with an addition of 30 seconds per move starting from move one. Here the increment starts from move 1.
How can I describe that in a formal notation? Is 40/90+30, SD/30+30 the correct way?
PGN standard has a different approach (the separator character is ":" and the increment is allowed only in the sudden death period, which is simply expressed in seconds):
but it seems the increment is not allowed for the first period (in case of a multi-period time conrol).
How can I express the FIDE TimeControl in the PGN tag as well? I tryed to download PGN games of FIDE events but I couldn't find any of them with TimeControl tag.