deleting this <meta name="robots" content="noindex" />?

[solook]

if  i delete this   <meta name="robots" content="noindex" />
is forum indexed good?

[karlbenson]

That line is important for some pages to prevent duplicate content being indexed (which is bad from an SEO point of view). It does NOT get included on every page, just a few duplicate ones.

It is best to leave it alone.

Search engines will still spider the majority of your pages and you won't get penalised for duplicated content.

[solook]

It is best to leave it alone.

so don't delete it ...
well
what most to do to make good Seo?

now some of my posts is not indexed and just index boarders..
what is  solution?

[karlbenson]

It has a purpose. So don't delete it.

The reason for it is that lots of links like the next/previous etc
http://www.simplemachines.org/community/index.php?topic=201692.0;prev_next=prev#new
will bring you to exactly the same content with a different url.
Search engines see this as duplicate content and you may get a negative seo effect.
So smf uses that line to show on duplicate pages to tell the search engine not to index that link because it maybe duplicate.

So it will NOT prevent your topics/posts being indexed.
The majority of your forum will be indexed fine.

Also be aware
It can take weeks to get initially listed in search engines
It can take months to get a more complete listing (eg lots of topic/posts listed).