said by Name Game:The following six characters are not allowed: ?, ", $, [, \, ] and +.
I did some checking and apparently the IEEE 802.11 standard doesn't say anything about prohibited characters. Cisco doesn't allow the ones you quote but other vendors do
I also found that although SSID's can be 32 chars long some devices only allow 31 (31 plus nul terminator makes 32 total).
quote:
The nice thing about standards is that you have so many to choose from.
Andrew S. Tanenbaum, Computer Networks, 2nd ed., p. 254