Much tidier than my white gloss paint running across each rug along the side - about 6" down from the withers and in 6" high letters & numbers
Note: if you remove a marked rug, try to spend 2 mins folding it so the marked part of it shows up clearly if a torch is shone round your storage area/stable etc. Some marked rugs still get nicked & dumped later when the thief finds it clearly marked, best to deter them 1st if you can.
Ours still get stolen with 1ft high letters in white gloss paint. Also postcode is no good if you share it with members of the no fixed abode community.