> How to mark frequences (for example in an entry of dictionary) ?
I'm guessing you don't mean something like
I listen to
<measure unit="MHz" quantity="1.29">1290</measure> AM,
my local public radio station.
She was somewhat tachycardic with a heart rate of
<measure unit="Hz" quantity="2">120</measure>.
More likely you mean word occurrence frequencies or some such. Any
chance you could give an example (preferably in English, but French
would probably do, too) of what you're trying to encode?