Flickr's Terms of Service  state that if you post an image hosted on Flickr on another site you have to  link back to the image page on Flickr. To do that you  need to go to your image  on Flickr, click on the All Sizes link above the image,  select the size image  you want, then Copy the HTML code from the first box of code underneath the  image. Then, in the Forum's Rich Text Editor, click on  the >> button/icon  and select Insert Raw HTML. This will open a frame  within your message where  you paste the HTML code you copied from the Flickr  site. Then continue on with  composing your forum message and click “Post Message”  to post the message to  the forum system.

For Pixentral images, you  will need to go to http://www.pixentral.com and upload your image following the  instructions there. You do NOT have to check the box to make images public. Once  your image is uploaded there copy the HTML code from the box below your image.  Then, in the Forum's Rich Text Editor, click on  the >> button/icon and  select Insert Raw HTML. This wil open a frame within your message where you  paste the HTML code you copied from the Pixentral site. Please note that there  is an extra "/" character in the Pixentral URL that will prevent the image from  showing up, so you need to make one change to the HTML that you copied from the  Pixentral site. The beginning of the HTML code  will look something like  this:

<a href="http:www.pixentral.com/show.php?picture=16xx5748rt9fhd"/>

Please remove the slash that appears between the quotes and the greater  than symbol so that this  part of the HTML code looks like this:

<a href="http:www.pixentral.com/show.php?picture=16xx5748rt9fhd">

Then continue on with  composing your forum message and click “Post Message” to  post the message to  the forum system.