"Don't use short tags, they may be disabled."
"Don't use short tags, they're deprected."
First of all, short tags aren't deprecated and never have been.
Second, there are actually TWO kinds of short tags, a regular one,
and a shorthand for echo,
Although the former can actually be disabled in configuration, the latter one "is always available regardless of the short_open_tag ini setting", as one can read on the manual page
While ranting on short tags, do not confuse them.
<?=is all right and extremely handy in native PHP templates.