CONSTANTS and PHP Class Definitions. Using define('MY_VAR', 'default value'). INSIDE a class definition does not work as expected. You have to use the PHP keyword 'const' and initialize it with a scalar value -- boolean, int, float, string (or array in PHP 5.6+) -- right away.
Prepositional Phrases. Do not use a comma between separate phrases unless they are in a series. A comma may also set off a single prepositional phrase at the beginning to make the sentence clear. A comma is recommended after any introductory prepositional phrase of more than four words. Correct: Under the kitchen table the dog cowered. (Single short, clear phrase.
A preposition sits in front of (is pre-positioned before) its object. It is useful to locate prepositional phrases in sentences since any noun or pronoun within the prepositional phrase must be the prepositions object and, therefore, cannot be misidentified as a verbs direct object.