Re: HTML tags for explanation purposes
That’s a single quote or apostrophe, not a back tick. On a US English keyboard, the single quote is on the same key with a double quote. The back tick is in the upper left corner or the keyboard, usually on the same key as the tilde (tilde requires shift.)
You want to use the upper left key in this keyboard layout around your code.
<?php e_('This is code'); ?> and ‘this is just inside single quotes’.