Also worth remembering buttonc's suggestion that if any non-standard opening is used, the detailed should automatically be noted in the Notes; this may prevent disputes later. i.e.
the Name of the opening e.g. C41: Philidor Defense: Philidor Countergambit, Zukertort Variation and optionally the FEN string ... 'rnbqkbnr/ppp3pp/3p4/4pp2/3PP3/2N2N2/PPP2PPP/R1BQKB1R b KQkq - 2 4';
When games (typically themed tournament games) start N moves along an opening, the initial moves are not recorded in the moves history.
Take for instance, Caro-Kann, Bronstein-Larsen Variation. Even when the tournament director is thoughtful enough to describe the initial sequence (as he did in this case: 1. e4 c6 2. d4 d5 3. Nc3 de 4. Nxe4 5. Nf6!? Nxf6+ 6. gxf6!?), it is not always convenient to refer back to the tournament notes - especially after the tournament has finished.
Consider recording ALL the moves in the history, please.