Enter a SWI name or number in the SWI search field and select the 'SWI' option. This search will match all SWI instructions that call that SWI, regardless of condition code or whether the X version of the SWI is used.
The mnemonic search matches a string you enter with any part of any instruction in the game. Since this search has to disassemble every instruction and do a sub-string search on them, it's quite slow. The string you search for is case- and spacing-insensitive, so searching for 'BCSR' would give an address contain the instruction 'SubCs R1,R1,#1'.
When this option on the Search window is set, the following characters are used as simple wildcards with the following meanings:
All the wildcards also match themselves, so 'a%c' matches all of 'abc', 'aGc' and 'a%c'.
Select the 'Coded' option to find text encoded in the simple way favoured by PD games authors who don't know any better, namely encoding each byte by an exclusive-or with a constant. Encoded strings found this way will not be visible in the disassembler, because they are still encoded. It is left as an exercise for the reader to take each byte and exclusive or it to find the real text.
Searching for references
Finding cheats