note 90568 rejected from regexp.reference by danbrown

Note Submitter: jon at phpsitesolutions dot com ---- As sengokyu mentioned, Redhat/Centos (as of 5.3) is still not using the current version of PCRE. (PCRE 6.6 is used, instead of the current 7.9) There are 2 issues here. 1. Unicode support: PCRE 6 supports Unicode, but Redhat compiled PCRE 6 without unicode support. You can get an updated RPM compiled properly, here: http://tiny.cc/redhat_pcre_6 2. PHP 5.2.4 adds support for \v, \V, \h, \H, but the docs fail to mention that these new flags are *only* available as of PCRE 7.2. Considering that Redhat/Centos is one of the most widely used server distros, it would be unwise to use those new PCRE flags, as they won't be supported on most servers that your code would run on Additionally, there are no intentions to update PCRE 6.6 to PCRE 7.x anytime soon, as there are many applications in Redhat/Centos that could be broken by PCRE 7.x (which apparently isn't 100% backwards compatible?). This is quite a shame, as these new PCRE features are quite handy...