Which is the meaning of the variables in the descriptions of the spell.dbc?

Hi, I am developing a website in which I want to show a tooltip talent of a player. I found in the spell.dbc file, the descriptions of the talents spells, but there are variables in the description. I need to know what they mean these variables, which is what they mean.
How I could find a complete description of all these variables?

Anyone has an answer please?

I’ve been around few years and I never saw those spell tooltip strings documented.