How to keep Spammers away in PHPBB

While setting up my own forums using PHPBB, I searched in internet, how to prevent spammers creating logins in my forum. This is want I found. I'm currently using v3.0.8.

Enable Q/A Captcha

Almost all types of Captcha can be broken by spam bots like xrumer which daily get advanced. Best is to enable "Q/A Captcha" in PHPBB. To do it in PHPBB:

• Login in into ACP
  
• General tab
  
• Board Configurations (in the left column)
  
• Spambot countermeasures (just search this string in the page)
  
• Press the Configure button(currently Q&A is disabled)
  
• Press Add
  
• Enter question & all the answers
  
• Go back and select Q&A in Installed plugins on the page ending: i=captcha&mode=visual
  

Example Q/A's

If yours is localized traffic then you can ask what is the capital of your state etc. If your site is on a personality like Emile Coue then you can ask the name of personality on whose your site is dedicated.
There is one site I've seen who ask anti-spam code which is located on another support page. So the user will need to go to support page, copy the code and go back to the Q/A and fill the fixed anti-spam code.
Read more.

Blocking UTC-12 Registrations

Most of the bots try to register with UTC-12 time zone and no human being uses it. So block it by making changes in the code(find it here)

Disabling BBCODE URL

Disable BBCODE URL in posting as well as in signatures. This will act as deterrent to spammers. Go to General->Board Configuration->post settings->Allow links in posts/private messages. Set it to no. Similarly go to General->Board Configuration->Signature settings->Allow use of links in user signatures and set it to no.

Add nofollow in all links

Even if you allow BBCODE URL in the site, it's good to add nofollow with all links. This will discourage many spammers. Check out this link.

Disable Website link in Profile

In the default installation, only registered users will be able to see the profiles. So you are already safe. But if later to allow the unregistered public(including search engines) to view profiles, use this technique mentioned here to disable website link in the profile. This link discusses how to disable website in thru the theme template.

Unregistered User Group

By default when a user is in unregistered user group and initial posts are all moderated. So you are safe. Even if you want to remove all moderation for even first post then you can set specific permissions for this group.

Make Profile
Visible only to Registered Users

This feature come on by default in PHPBB. It is a nuisance
in new forums that spammers create account only to put links
in their profile. If they are not visible to Guests then it
won't be visible to Search Engines too. Spammers will
find no use in your forum!