Each request should be considered individually and take into account factors such as the pupil's age, the timing of the proposed holiday and the overall attendance pattern of the pupil.
As well as the timing and wording of the ballot, the two sides have disagreed on whether the voting age should be lowered for the referendum (Mr Salmond says that it should) and whether it should be overseen by the Electoral Commission, which Nationalists testily point out is answerable to the Westminster Parliament.