Template:Dfn/testcases

Some wording from the docs with test cases
If there would be a " " (equals sign) in the term, either a) both unnamed parameters if present must explicitly be numbered:
 * Live: which results in:
 * Sandbox: which results in:

or b) the character itself can be escaped as the HTML character entity reference code  or the  template:

Live:
 * which results in:
 * which results in:

Sandbox:
 * which results in:
 * which results in:

For technical reasons, the second parameter (2, the definition ) is more "brittle". The equals sign must be escaped by one of the techniques just mentioned,  the standard keyboard (straight, not curly) double-quotation mark  must also be escaped, no matter what, as   or. This double-quote must also be escaped the same way in the title parameter:

Live:
 * which results in:
 * which results in:
 * which results in:
 * which results in:
 * results in:

Sandbox:
 * which results in:
 * which results in:
 * which results in:
 * which results in:
 * results in:

...

Linked version:

Live:

gives:
 * Mass–energy equivalence

Sandbox:

gives:
 * Mass–energy equivalence

It still has a dotted underline indicating a tooltip, but is also a bluelink. Mouse hovering shows both the tooltip and, in the status bar, the target URL, in browsers that support these features.

It still has a dotted underline indicating a tooltip, but is also a bluelink. Mouse hovering shows both the tooltip and, in the status bar, the target URL, in browsers that support these features.

Link inside the :

Live:

results in:

Sandbox:

results in:

This doesn't mess up the page, but the description fails and there's no tooltip cursor, meanwhile the markup is hard for other editors to understand anyway so it is deprecated.