We use the following standard terms and abbreviations to indicate the condition of the stamps that we sell.
CTO – Cancelled to Order
A stamp that appears to be used (i.e. it has a postmark), but still has gum on the reverse.
They are so-called because they are cancelled by the issuing postal service before being sold to stamp collectors or dealers – for example, to meet collector demand, or so that they can no longer be used on mail.
With some local stamps, such as those from Staffa, the only stamps that exist are ones in CTO condition – they were never made available in mint condition, and did not perform a postal function in order to become properly ‘used’.
F/U – Fine Used
Postally used, with a particularly clean or neat postmark; better than ‘good used’.
G/U – Good Used
Postally used, but with a postmark that is less neat, or covers more of the design, than a stamp that is ‘fine used’.
U/M – Unmounted Mint / MNH – Mint Never Hinged
Synonymous terms for unused and never-hinged stamps, as bought from the post office, with the gum on the back fully intact; more desirable than ‘mounted mint’.
M/M – Mounted Mint / MH – Mint Hinged
Unused, but previously hinged for display in a stamp album; less desirable than ‘unmounted mint’, but still collectable, and usually cheaper!
These days, most stamp collectors know better than to hinge mint stamps – that’s what stockbooks, mounts, and albums with plastic pockets are for – but it was normal to use hinges until the 1970s, which is why you may particularly find older mint stamps with hinge marks.