Why is this other domain coded in my htaccess?

I checked my htaccess today and saw a RewriteCond for another domain there

[FlashDriveDT]

First of all please understand that I'm quite a noobie when it comes to htaccess. Today I discovered that I had a domain named www.othersite.com in my htaccess. My whole file looks like this:

RewriteEngine on

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://example.net/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://example.net$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.example.net/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.example.net$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.othersite.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.othersite.com$ [NC]
RewriteRule .*\.(jpg¦jpeg¦gif¦png¦bmp)$ - [F,NC]

www.example.net is my own domain of course. Do I need to be concerned about this? othersite.com is a regular website and I saw that my profile is featured on their homepage (the username is also FlashDriveDT). I suspect that this is the reason their domain is showing up in my htaccess. But why? Is this benefitting or hurting me? The profile display over there gives me traffic of course and two backlinks are featured there but what does that have to do with my htaccess?

On a second note - I found this out because I wanted to check why this plugin isn't working for me that is suppose to rewrite my htaccess (the plugin is called wp-supercache and is suppose to make blogs load faster). Well, apparently it isn't able to and Im suspecting this othersite.com could be to blame for that? How do I make my htaccess rewritable by this plugin? When I right click on the htaccess file via ftp client I see that the rights are set as follows:

administrator rights: read (checked) write (checked) execute (unchecked)
group rights: read (checked) write (unchecked) execute (unchecked)
public rights: read (checked) write (unchecked) execute (unchecked)

Do I need to change something here?

I would very much appreciate some insight and help. Thanks!

[edited by: jdMorgan at 1:42 am (utc) on Dec. 21, 2009]
[edit reason] No domains or URLs, please. See TOS. [/edit]

[FlashDriveDT]

After doing some thinking I believe this stems from an exclusion request in my cpanel's "hotlink protection". For some reason I also have my own website listed on that exclusion list and hence it shows up in my htaccess. Is this actually necessary? I dont remember if my site was there by default or if I added it. Thanks for any feedback!

[FlashDriveDT]

After doing some thinking I believe this stems from an exclusion request in my cpanel's "hotlink protection". For some reason I also have my own website listed on that exclusion list and hence it shows up in my htaccess. Is this actually necessary? I dont remember if my site was there by default or if I added it. Thanks for any feedback!

[g1smd]

The code lists the domains that can link to, and show, your images on their pages.

If it isn't listed, none of the images will appear on the pages of that site.

Your own site has to be on the list, by definition.

The list is very inefficiently coded though. There is a lot of redundancy in the code.