British Commonwealth
Mint / Unused
Stamps are primarily intended for use on mail, when they are usually found cancelled to prevent fraudulent re-use, but can often be found used for fiscal, telegraphic or other non-postal purposes. Stamps that have not been used for these purposes, remaining uncancelled and ideally in the state in which they could have been purchased over a Post Office counter, are known as 'mint'. 'Unused' denotes a stamp without gum, which might be because it was sensible to issue stamps in this way because a hot and humid climate would make them stick together; it is generally regarded as preferable to collect stamps with gum where possible, but 'unused' may be a less expensive (or the only) way to fill a gap.