Is it by the number of the votes or author of the topic can mark it as Identified?

Only the moderators can mark the suggestions as 'green'. But if there's a disagreement, they can always change it back.

Is there a specific topic you are referring to?

I got 3 topics that needs to be marked as green.

http://www.dafont.com/forum/read/123202/font-on-hellertown-borough-pennsylvania-police-vehicle
http://www.dafont.com/forum/read/117753/croatian-police
http://www.dafont.com/forum/read/117520/font-used-on-croatian-number-plates

So in the future, do I have to ask moderators or will they after some time mark topic as green?

— First link : We usually don't mark these cases green unless we're 100% sure whether it's Eurostile or Square 721 (or sometimes Microgramma). It's a long story, but it's particular to these 3 fonts...

— Second link : I'm really not sure it's the exact font, the 'O', in particular, looks different.

— Last link : In this case, the person who made the suggestion had the ability to mark its answer and chose not to. But... it isn't really a font is it? I mean, it's not like the Croatian government came here and chose this font for their licence plates? Or maybe they did?

But I must agree : Most (if not all) of them could have ended up green since they are all soooo close.

1. It could be Microgamma font?
2. To me it looks the same, sometimes this fonts are giving me headaches because there are always few fonts that look the same and I have to stare at them for hours thinking which one to use.
3. That one is closest one.

I think that there should be the option for the author of the topic to set it as green.

1. No. Look at the 1 in 911.
2. Story of my life.
3. I agree. You may ask Koeiekat for his opinion.

I strongly disagree. It would be a damn mess. Bebas... Bebas everywhere!

1. Then it's probably double extended bold Eurostile.

As for the first one, the nine says Microgramma but the one forbids. It may be something like the Image Club Graphics' Micro Technic Extended Bold.
As for two, the same story. Eurostile is the original Microgramma with added lower case. Microgramma only had capital letters. Bitstream's Square is the Eurostile, made with the original Linotype material and thereafter copied a million times over with minuscule variations in details.
As for three, it is no match, only similar.
As for all three, CAD and CAM programs will never produce a result that is exactly the same as the original typeface. So in cases like these three it is always a bit of a gamble. And I will not mark green when it is not a perfect match. I know that some here do when it is in their opinion a reasonable lookalike, but I will not.