$re = '/[vn]\.?\s*(C(hr?)?\.?|(Z(tr?)?\.?))/mi';
$str = 'vc
vc.
vch
vchr
v.C
v.C.
v. Ch
v. Ch.
v. Chr.↵
vz
vz.
vzt
vztr
v.Z
v.Z.
v. Zt
v. Zt.
v. Ztr.↵
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php