I have been asked by a synagogue if they could make some mark on their sifrey torah so they would be traceable if stolen and they wonder if marking them would make them unkosher. I recall reading halacha around marking k'laf with a series of holes in a pattern which would be acceptable. I have even seen a torah with a kind of hechsher stamp from the magihah, but they have asked about using Crimestoppers Property Marker kits to leave a small drop of clear liquid on each valuable item (one assumes the silverware too) as recommended by the police in the UK - I think this is some kind of invisible ink that shows up under ultra violet light only. Much of halacha around holes etc is regarding something visible to the naked eye. Would this fall under that category. What are other sofrim advising people who wish to protect their sifrey from theft/make it easier to identify/recover the sefer if it was - chas v'shalom - stolen.
Interested in both the halacha and the practical options here.