If you can earn a banner by doing a geocache, it is common to put, besides the banner itself, the html-code of the banner on your geocache page. It makes it easier for the other geocachers to put the banner on their profile or any other webpage. How to put an image (banner) on a geocache page is explained here.
To put the html-code on the geocache page we need a little tric, otherwise the image will be shown instead of the code itself. The tric is to replace the < and the > in the code by the html-code for these characters, which is < and >. This results in:
Original code: <img src="Image location" alt="Description" title="Description">
New code: <img src="Image location" alt="Description" title="Description">
Replace all occurrences of < and > by < and > and put this as html-code on the geocachepage.
A handy tool for this is the Image code generator.