I don't know if there are any stores for bark localy arround you, arround me the ones that sell it locally sell stuff I would not use as it's not been stored correctly and is already decaying.
For that reason I always buy medium from an orchid specialist online (see my link in an earlier post). It does of course mean you have to pay postage but I've found it much higher quality.
S/H means semi-hydroponic. It's a method of growing which uses a much wetter enviroment with clay pellets as the medium.
This link has all the info about S/H and we also have a section on the forum for people discussing it.
Semi-hydroponics