I sometimes discover lost dogs on the street that have a collar with a tag with maybe a contact phone to reach their owner.

Since I don't know their character or if something happened and scared them or made them nervous, I have to admit I am a bit scared to put my hand under their mouth and reach for their collar tag.

My question is: What is the best and safest way to reach and read the tag on the collar of a lost dog that you haven't met before, without risking your hand being bitten?