What's a correct naming scheme for PHP extensions (written on compiled language, e.g. C)?

[Sergey B Kirpichev <skirpichev@gmail.com>]

Here is
http://webapps-common.alioth.debian.org/draft-php/html/ch-php-int.html#s-php-interpreter-naming
which describe naming convention:
----->8----
phpPHPVERSION-PHPMODULENAME
One of a small collection of prebuilt php modules such as
php4-mysql, which are included with PHP by the upstream authors.
---->8----
and policy for naming PEAR libraries:
http://webapps-common.alioth.debian.org/draft-php/html/ch-php-libs.html#s-php-libs-pear
--->8----
Debianized PHP libraries should be prefixed to identify themselves as
such. The naming
scheme should follow that of other languages (such as perl, ruby, and
python) and name
packages in the form libPEARLIBRARYNAME-php. Optionally, if the php
library only works
with a specific version of php libPEARLIBRARYNAME-phpPHPVERSION. would
also be acceptable.
--->8----

The first is for core PHP modules, the later looks like for
written in PHP libraries (e.g. requirement: "PHP libraries should
be located in /usr/share/php/PACKAGE").

What's a correct naming scheme for PHP external extensions (not in core), either
from pecl.php.net or not: phpVERSION-EXTENSIONNAME (e.g.: php5-xcache,
php5-geoip) or libEXTENSIONNAME-php (e.g.: libssh2-php).  The first
one seems to be more popular.

PS: Please CC me if you answer on this, I'm not subscribed to this list.