From Masq

+prove <stat>=<number> to <player>

The first form of this command proves that you have at least <number> in any ability, attribute, virtue or background that you possess, for the purposes of judgeless roleplay. You may choose to 'underdeclare' your abilities should you so desire.

When this command is processed, you and your target receive an alphabetic <code>; this can then be verified with the second form of the command.

For example,
> +prove Strength=1 to Bubba PROVE (IXUO) Ryan's Strength is at least 1.