Complex sentence: Unlike standard cancellation marks, they do not give a specific date, affording the bulk purchaser time to use them at their discretion, in some situations, months or years may be included in the overprint to indicate a long-term expiration.
Split into simpler sentences: Unlike standard cancellation marks, they do not give a specific date, affording the bulk purchaser time to use them at their discretion. In some situations, months or years may be included in the overprint to indicate a long-term expiration.