I have a page shirts.php which lists all the shirts, and then I have a page product.php?id=X, which displays the individual product information.
If I write the rule like this:
RewriteRule ^mens_shirts/([0-9]+)$ product.php?id=$1 [L]
and the input url is mens_shirts/22
it displays the product page correctly with the clean URL.
However, if I write the rule like follows:
RewriteRule ^shirts/([0-9]+)$ product.php?id=$1 [L]
and the input url is /shirts/20
, instead of displaying the product page, it displays shirts.php.