XML code . How to use

I've seen here at the forum many useful XML code examples. I tried to use some in buttons. Bur when I paste the code to the command editor and try, it doesn't work. In the documentation I don't see anything about this.

So, my ignorance question is how do I use this code?

Paste it directly to the toolbar (in Customize mode, right-click on an empty space and choose Paste)

There's a detailed FAQ on this: [How to use buttons and scripts from this forum)


Very simple anyway.