###Yes, this exists as a feature of all sites in the StackExchange system (to my knowledge), which includes StackOverflow and all the other StackExchange sites.

HOWEVER, it's a privilege that you need to unlock on a per-site basis, by gaining rep on each individual site.

You need obtain and then maintain 1,000 or more reputation points to get that privilege.

According to your list of other accounts on your main profile page, only Ask Ubuntu is where you have over 1000 rep. So you haven't unlocked the feature anywhere else.:

Yes, this exists as a feature of all sites in the StackExchange system (to my knowledge), which includes StackOverflow and all the other StackExchange sites.

HOWEVER, it's a privilege that you need to unlock on a per-site basis, by gaining rep on each individual site.

You need obtain and then maintain 1,000 or more reputation points to get that privilege.

According to your list of other accounts on your main profile page, only Ask Ubuntu is where you have over 1000 rep. So you haven't unlocked the feature anywhere else.:

##Yes, it exists on other sites.

HOWEVER, it's a privilege that you need to unlock by gaining rep on the other sites.

You need 1000 reputation to get that privilege.

According to your list of other accounts on your main profile page, only Ask Ubuntu is where you have over 1000 rep. So you haven't unlocked the feature anywhere else.:

###Yes, this exists as a feature of all sites in the StackExchange system (to my knowledge), which includes StackOverflow and all the other StackExchange sites.

HOWEVER, it's a privilege that you need to unlock on a per-site basis, by gaining rep on each individual site.

You need obtain and then maintain 1,000 or more reputation points to get that privilege.

According to your list of other accounts on your main profile page, only Ask Ubuntu is where you have over 1000 rep. So you haven't unlocked the feature anywhere else.: