Add a new group setting that allows people in that group to receive notifications via PM or email if specific keywords are used within a post. I think it might be resource intensive though, as each post and reply would be scanned for those keywords before inserting it into the database.

I myself would use it to scan for keywords like forums, website, attach, etc... because I can't read every single new post made on my forums and sometimes people will make a post embedded deep within a topic saying they couldn't get x to work with the forums or something is broken.

Here is a classical design rule:
how often does the application receive a request? if it's not even every sec, don't worry too much about performance.

I use a tagging/keyword type of system that I added on to a component I use and I thought of doing some sort of notifications also, but like you said it probably would be resource intensive. Most things I personally create I do without even thinking about resources being utilized. lol

And by the way doing keyword systems is not hard at all. I think a lot of things suggested here are deemed difficult in posts by staff when I personally don't see them as being difficult. But of course I am not an expert at every ounce of the forum software so it may indeed be mroe complicated for IPB since it may affect something else which I don't know about in some other files.

Funny you mentioned this. We just created a component+mod exactly like this for a client that wanted specialized doctors to get emails about words used related to their field of work. I wonder why something like this is becoming more popular lately.

I could see it being more a subscribe to feature.

So the user sets a rule in the My Controls that has something like:

if title contains, ect
if body contains, ect

Like the e-mail rules you can create. Although for wide spread use I don't think I'd really use it, rather leave it to a modification.

Honestly, it is no speed impact at all, the forum is already doing far worse things as part of the formating engine.

Honestly, it is no speed impact at all, the forum is already doing far worse things as part of the formating engine.

Agreed...the comprehensive parsing for bbcodes is much more resource intensive than parsing for keywords.

Unless you add 50,000 keywords or something...