My job involves the specifying of fire door signage for new doorsets and one anomaly is what to use when working with pairs of doors where each leaf has a different operation. The legislation is clear in determining the type of sign for the 'door' but less so when the 'doors' are not identical. Here's what I do, would appreciate any feedback: Equal pairs with identical characteristics are simple - signage should be the same on each door, 'Fire Door Keep Shut', Fire Door Keep Locked' or 'Automatic Fire Door Keep Clear' (to suit). It's typical to see '...Locked' signs to the corridor/visible side only. There is some advice suggesting that 'Automatic Fire Door Keep Clear' can be fitted to only the side visible when the door is held open, however as these could technically be double action and held open from either direction (rare but not unheard of), I would always use these and '...Shut' signage on both sides. Equal or unequal pairs where door operation (hardware) is different between leaves are a little more complicated as the signage should reflect what each leaf is doing. For example: Pair of doors with primary leaf fitted with closer and secondary leaf bolted shut. I've seen these specified with 'Fire Door Keep Shut' signs on just the primary leaf. I've also seen the same signs on both doors. I don't see either as being correct. The signage most suited for this configuration would be 'Fire Door Keep Shut' to both sides of the primary leaf and 'Fire Door Keep Locked' to both sides of the secondary leaf. Now imagine the same doors but with a door closer fitted to the secondary leaf. This should also dictate a change of signage (for that door), to give 'Fire Door Keep Shut' on both sides of both doors.