Why do manhole covers have to be marked with purpose or logo?

It's simple. If you don't mark the purpose on the manhole cover, you can't tell which manhole cover is used for what. There are too many manhole covers on one road. If there is a problem that needs maintenance, even if we don't know what the manhole cover is for, the follow-up work will be difficult to carry out and even serious accidents will occur.

So the manhole cover will definitely indicate what the manhole cover is for. For example, various types of manhole covers in Zhenjin, Hunan Province will be marked as rain wells, sewage wells, power manhole covers or communication manhole covers, and some will also indicate the units to which the manhole covers belong, which is more conducive to municipal management.