I wanted to use the excellent [Acronym Replacer][ar] plugin in my [WordPress][wp] installation. But I also wanted to use the equally excellent Markdown plugin delivered with WordPress 1.2 Beta. Download, install, activate. Everything went fine, except for the fact that the feeds were completely broke: The Acronyms were duly replaced, but Markdown didn’t seem to work anymore. Well. I filed the obligatory bug report on the forums but was quite desperate to find a solution. One thing, however, struck my attention when I peeked into the acronyms.php file. 
add_filter('the_content', 'acronyms', 8 );
add_filter('comment_text', 'acronyms', 8 );
Obviously, there seemed to be something that *could be* some kind of priority. But what kind? Some more diggin’ and functions.php surfaced with the function definition for add_filter() 
function add_filter($tag, $function_to_add, $priority = 10 )
Well, a good start. I changed the priority of the acronyms.php to something *bigger* than markdown’s standard of **10** and — *voilà* — it works. Upon further notice, I consider this problem as solved. (Can anyone tell my why a *bigger* priority actually means less priority?) So, if you run into the same problem, here’s what the add_filter statements must look like: 
add_filter('the_content', 'acronyms', 12 );
add_filter('comment_text', 'acronyms', 12 );
[ar]: http://www.huddledmasses.org/2004/04/19/wordpress-plugin-acronym-replacer/ [wp]: http://wordpress.org