Another method is to view the output by f60gen. Note:283985.1 provides a script which will determine the patchset level for you. You don't really need a script for it tho.
Execute f60gen and look at the first line:
Forms 6.0 (Form Compiler) Version 220.127.116.11.0 (Production)
Subtract 9 from 27 and you'll have your patchset level. So I am on patchset level 18.