Includding callaouts inside paragraphs

Hello fellow doc writes,

I've found the following snippet can be used to include callout icons (if :icon: 'font' is set of course) inside text paragraphs:

    [conum,data-value=1]_1_

where 1 can be any number. I wonder if there's a better, shorter way to achieve the same goal? Also, is this portable across different backends? So far I've tested it with HTML5 because that's my current target.

Cheers,
Andres