[CalvinC]

The dialog ID.
Each dialog has it's own dialogid, to be used in OnDialogResponse where you can script different functions for different dialog ID's.
Basically some people use

pawn Код:

#define DIALOG_CMDS 1

Which makes

pawn Код:

ShowPlayerDialog(playerid, 1, ...);

The same as doing

pawn Код:

ShowPlayerDialog(playerid, DIALOG_CMDS, ...);

Which is more organised, and less confusing.
However using an enumerator is even less confusing, as it applies the ID's(numbers) automatically.