Pattern rules:
--------------
case insensitive
[]     variable residues are surrounded by squared brakets
.      a completely variable residue
+      one or more residues, e.g. S+ for consecutive serines
*      zero or more residues
{a,b}  repeated between a and b times (or any time if b non-specified)
|      separate variants of a pattern
()     subsequences; above modifiers applies, e.g. (GGGGS){3,3} will
       search GGGGS repeated 3 times
^      restrict to the beginning of a sequence
$      restrict to the end of a sequence

Example: atg(...)+(tag|taa|tga) will find ORFs!
         [VILMFWC]{10,} for finding stretches of 10 or more hydrophobic residues.