php 7 other changes
Globally reserved words as property, constant, and method names within classes, interfaces, and traits are now allowed. This reduces the surface of BC breaks when new keywords are introduced and avoids naming restrictions on APIs.
This is particularly useful when creating internal DSLs with fluent interfaces:
<?php // 'new', 'private', and 'for' were previously unusable Project::new('Project Name')->private()->for('purpose here')->with('username here'); ?>
The only limitation is that the class keyword still cannot be used as a constant name, otherwise it would conflict with the class name resolution syntax (ClassName::class)
Content taken from php.net