I think I have figured it out. First, I uploaded photos and created a "Photostream" or "Set" of photos as they call it...
http://www.flickr.com/photos/davydd/sets/72157613609412154/ Then I double-clicked on one of the photos to bring up this page...
http://www.flickr.com/photos/davydd/3269356643/in/set-72157613609412154/ Then I selected "All Sizes", one of the small options you see right above the photo...
http://www.flickr.com/photos/davydd/3269356643/sizes/o/in/set-72157613609412154/ You are presented with Square, Thumbnail, Small, Medium and Large options. Select the one you want then copy the "Option 2" URL address at the bottom of the page. This is the URL...
http://farm4.static.flickr.com/3467/3269356643_74b7b647e0_o.jpg Enclose that URL in the [img][/img] HTML code and get...
Warning! Right below option 2 is this reminder...
Remember! Flickr Community Guidelines specify that if you post a Flickr photo on an external website, the photo must link back to its photo page. (So, use Option 1.)
Flickr Community Guidelines say to this about linking back to Flickr.
Do link back to Flickr when you post your Flickr content elsewhere. The Flickr service makes it possible to post content hosted on Flickr to outside web sites. However, pages on other web sites that display content hosted on flickr.com must provide a link from each photo or video back to its page on Flickr.
I guess I am legal because I have provided several links back to Flickr in this message that you can follow along with the explanations. It is kind of confusing to me.
Photobucket.com is much easier and does not have that condition.
The tenderloin sandwich, BTW, is the Dairy Sweet in Dunlap, IA, the 2005 Iowa Pork Producers Association best breaded pork tenderloin winner.