If the photographs are already on Flickr, then you just need the image code. Above each image in Flickr, you will see a button that is labeled "Share". Click it. A box that will appear that is the image's URL address. Copy this address.
Then when you go to submit a "Reply" here on PFF you will notice on the area above the reply text box there is a button labeled "Image". Click on this and paste the image URL into the box that pops up. What this will do is encase your URL into [IMG] [/IMG] brackets, allowing the image to show up on the forum.
It may not work for some images. Flickr has issues sometimes showing images on webpages. I would recommend you use PIP here on PFF (it's at the bottom of every forum page), or use another image hosting site like Photobucket.
Do note that if you use any external image service like Flickr or Photobucket you can NEVER remove the images from where you upload them. If you do, they disappear from here. PIP is the only definitive means by which to ensure the images you upload will always be here.
[This message has been edited by Fiero84Freak (edited 02-06-2013).]
