Hide a Public Forum?

[Maalong]

Is there any way that I can hide a public board, from the Forums but have it show when called from a specific Menu link?

For example, if I have the following forums:

Private Boards (Parent only visible to mods and admins)
     Private Board 1
     Private Board 2

Public Boards (Parent visible to everyone)
     Public Board 1
     Public Board 2
     Public Board 3 (I want to hide this board from the forums)

What I want is to hide Public Board 3, but in the ACP Menu Manager, create a new item with an external link to Public Board 3, so that if clicked it opens the Public Board 3, otherwise it is not viewable.

Hope this is not too convoluted an explanation, and that someone can help.

[opentype]

[data-forumid="XX"] { display:none;}

Put this in the custom.css and and replace XX with the ID of the specific forum. 

[Maalong]

Hi opentype,

Thanks very much for that! Works perfectly, though took me a couple of tries to figure out what to do as I am new to dealing with Themes and CSS.

So, for anyone else as inexperienced as me that wants to do this, this is what got it to work:

1. Open the ACP
2. Go to Customization >> Themes
3. Choose </> Edit HTML and CSS, in the default Theme
4. Choose the CSS Tab
5. Find custom.css under Core >> Front >> Custom
6. Add in the code as shown by opentype
7. Change the XX to just the ID number of the forum, found in the forum URL
8. Save the CSS 

Again, many thanks opentype!