A measure of one's psionic ability: the power of the mind and will to invoke effects directly. Wyrm's site says, “You may not know it, but there are those who can read your mind like a magazine, or move objects just by thinking. You can indicate your strength in Psionics using this tag.”
As with magical ability, positives represent an ability to use psionics, while negatives represent a passive, inherent interference with them, as opposed to using psionics to block psionic powers.
Wyrm's site makes a point of noting that the traditional descriptions are illustrative of one's level of ability rather than descriptive of the kind of powers available.
There's almost nothing I can't do if I put my mind to it.
I can move mountains, and not bit by bit!
I know what you're thinking… did I use six psychic blasts or only five!!!
I can talk to the odd spirit, or move very small rocks (churches, lead, ducks, etc.).
I'm like a book, but haven't learned to read myself yet!
Psychics have trouble communicating when I'm around.
Only my very outer thoughts are exposed.
Psionics just don't seem to have any affect.
Not only am I immune to any Psionic effect, but I prevent them happening around me as well.
As with magic, if you have a particular specialty, it can be enclosed in square brackets after the rest of the tag. Wyrm's site suggests trying to abbreviate if possible, though it offers only one particular example: V++[tk] indicates “I am fairly good at telekinesis.”