Why doesn't RP have a function to avoid duplicate links being posted?

Admins can close duplicate links if they feel it is necessary. However, we focus primarily on duplicate or irrelevant questions/answers. SSG Carlos Madden SSG James J. Palmer IV aka "JP4" may be able to speak a little more on this.

They do! It's called two star - four star admins. ;)

I know other sights do... Should be easy...