I needed to use one in a recent post and had to figure out how it was done.
There are no keys on the key board for these symbols, so it must be some sort of code.
Searching around brought me to a page with some html code that would get the job done.
And it really works quite easily.
I have only needed a couple of them so I will share what I have learned so far.
These codes are entered as you normally type - as in the compose screen on blogger.
You type the word you need with the symbol, then do this action without any spaces after your word:
hold down the alt key and press 0174 for the registered symbol = ®
hold down the alt key and press 0169 for the copyright symbol = ©
hold down the alt key and press 0153 for the trademark symbol = ™
It's kind of neat how they "pop" up when the alt key is released.
I will add more when I need and find them.