A flexible share-counting provision in a stock plan that varies its treatment of different types of stock grants for the purposes of determining how many shares have been used and how many remain. While stock options may reduce the plan reserve by one share for each option granted, restricted stock or RSUs ("full value awards") reduce the pool by a greater number (e.g. two shares for each RSU granted) because they have a higher accounting value under FAS 123(R) (now called ASC Topic 718). This also reflects the higher value/cost that institutional investors and proxy advisory firms (e.g. Risk Metrics) place on full value awards when evaluating a company's stock plan. (In case you were wondering, fungible is a legal term that essentially means "interchangeable".)