[chrishajer]

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.)

http://upload.wikimedia.org/wikipedia/en/5/51/KB_United_States-NoAltGr.svg

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’.