kinshi-suru, "to prohibit".
This is a very common concept, and in a social life one has be face many and various prohibitions. Today I saw a sign on a toilet door to remind customers not bring a merchandise into there. However, the expression comes with this one was rather extraordinary. In stead of using "する", this sign says "禁止させていただいております". I started to think how shall I explain this one to my young students, and in fact, whether or not it is possible.
I guess one may want to argue that this is a Japanese honorific expression. However, does a customer indeed received a respect through this expression?