i'd like to create a little catalogue website. i have a set of pre-defined tags i want to use, like "green", "yellow", "black", "t-shirt", "pants", "hoodie", etc. i made a form with checkboxes (the values are the tags), the user checks some of it, then s/he gets the results.
the question: is there an "OR" relation in wp? i know that i can use "AND" relation between tags, eg.: http://www.example.com/wordpress/tags/black+hoodie/... but in some cases it would be better if i could use "OR", for example if the user checks more colors. /tags/black|green+hoodie/... (the "AND" reduces the results, the "OR" would expand it...)