How to close a forum from indexing leaving only a few topics open for robots?

Question

Search Engine Optimization

There is a site with an old and very cluttered forum completely closed from indexing, in which several topics are of value. It is closed by means of Disallow: /forum/ in Robots.txt How can these topics be opened for robots? Will it work by adding Allow: /forum/goodthemes/ to robots? Thanks in advance.

Answer 1

Solved the problem like this.
Because Google and Yandex are friends with the Allow directive, do the following.
We close from indexing all pages starting with forum:
Disallow: /forum/
But we allow indexing pages starting with forum/viewforum and /forum/viewtopic:
Allow: /forum/viewforum
Allow: /forum/viewtopic
Accordingly, pages like /forum/ will be indexed viewforum.php&f=31 and the like.
There is quite a bit of information on the subject here .
If someone can add or provide alternative solutions, I will be grateful.