When searching for duplicates of a question often multiple ones turn up, but when voting to close only one of them can be specified.
It would be useful to be able to add more than one duplicate link when voting to close.
I disagree. The point of exact duplicate is that there is one primary question to which all others should refer. This excludes questions which may be useful, but are not EXACT duplicates - those can be posted in an answer or comment to the question.
If you find multiple EXACT duplicates please determine which one should be the parent and mark the newer question as an exact duplicate of the parent. The parent is usually the oldest question, but sometimes a newer question with more information or which is phrased better might be a better choice.
Then vote to close all other exact duplicates with the same parent. Consider posting a message here on meta so that other moderators can consider your request and close questions which might not otherwise receive enough votes for close as they've fallen off the front page.
But PLEASE do NOT promulgate multiple "exact" duplicates. The point of duplicate identification and closing is to shunt all the best information for a given problem into one spot.
This is a very needed feature. Just today I ran into a triply duplicated question and promptly violated the don't edit to add duplicate links rule (of which I was blissfully unaware until it was recently bumped).
Although the Community User process will edit all duplicates, we can only specify one per close vote. We need to be able to specify more than one dupe on a close vote.
I've already voted to close. Can others help @mmyers out?