From that source:
Section 302 is the part of the Act relating to treatment without consent for observed behavior constituting a clear and present danger to the individual and/or others. The behavior must have occurred in the past 30 days. Under Section 302(a) any responsible party can petition for an involuntary evaluation by stating that an individual may be severely mentally disabled.
I know a guy here in Pennsylvania who rants and raves about how priests' abuse of children is equivalent to <a href="http://www.foxnews.com/story/0,2933,84862,00.html">"basic homosexual relationships"</a>, that upholding the right to consensual sex leads to <a href="http://www.foxnews.com/story/0,2933,84862,00.html">bigamy, polygamy, incest and adultery</a>, and who brought a deceased five-month-old fetus home for his <a href="http://www.signorile.com/articles/nyp75.html">kids to hold</a>.
How does one start the process of petitioning?