What does the "Not Sure" chat flag response do?

Question

Pretty straightforward here...

When a chat flag appears for 10k+ users, we are given three options.

1. Valid
2. Invalid
3. Not Sure

After reading this post, I am... not sure... what the third option does. Since the SE Network has sites dedicated to languages other than English, chat messages may also be in other languages. When confronted with flags on messages written in a language I do not understand, I have been clicking "not sure". Is this the proper thing to do? Does a "not sure" response have any effect in the review process (i.e. a certain number of "not sure" responses remove the flag from review)?

Answer 1

The "Not Sure" flag response counts for approximately 1/5 of a flag:

The "meh" votes are taken into account with a ratio of 1:5 (and rounded downwards); in other words, for every five people doing nothing with the flag, we deduct one from the net count.

-- balpha

The 'net count' in context means the total number of valid flags minus invalid flags, and a flag is marked as valid when the net count reaches +6.

It's not stated in that answer whether a net count of -6 will decline the flag, but I'd assume either that or when a total of x people have voted on the flag without it hitting +6.

Also note:

These are the current numbers ("current" because they can obviously be changed, but there aren't any plans to do so; they have been like this for a while):

It's obviously not likely, but it's possible they have been changed or will be changed.