If you know what a URL is, then what you’re doing is pasting a “friendly text label” next to the URL for a link, separated by a colon, and with no extra spaces on either side of the colon.
If you don’t know what a URL is, then you need to look that up. It’s defined in other places better than I can hope to do it here.
Every question on Fluther has a unique URL. As a matter of fact, each RESPONSE on Fluther also has a unique URL. (If you hover your cursor to the right of the “Flag as…” link on every response you should be able to make the “Permalink for this response” link appear. Go ahead and click on that link. I dare you. It won’t hurt a bit.) That will take you to the specific URL for any individual response, so if you want to link to a specific response, you’ll want to click on the permalink so that you can easily acquire the response’s URL for pasting.
So, for example, to show how to link to Your Profile, all you need to do is type
“Your Profile, (You can also include tags, and I’ll show that process, too!)” : http://www.fluther.com/users/Love_my_doggie/ and just leave out the spaces on either side of the colon. (Links without “friendly text” will be highlighted the way links usually are, as you can see in this example.)
There are some caveats.
Many links, such as the extremely long strings that one finds on shopping sites such as Amazon, can become hashed in this process, so be aware of that and consider using URL-shortening services to make your long URL behave better. In addition to the foregoing, Wikipedia, for one, often includes underscore characters in the URL which seem to play hell with the “friendly text” tagging that Fluther uses, so watch out for that, too.
URL shorteners can often be very helpful, so that a URL such as “http://www.fluther.com/users/Love_my_doggie/” can be shortened to http://goo.gl/qDwsUJ (which is a real link, you might notice). That’s not so much, but URLs containing hundreds of characters can also be shortened to much more manageable length and handling.