How Links Behave

When you post a link and the link is defined at the beginning of a line, the link content is previewed like this:

If you find that this clutters up a post, you can stop this from happening by placing preceding characters in front of the line like this:

One clutter problem with previews links is that it is not clear where the clickable link really is.

And that preceding characters can be a single [space] character:
Steroid hormone - Wikipedia