If string with placeholders is requested by function _x(), but no parameters are given to replace placeholders with, the function can't return translated string.

Example: _x('Added, %1$s', ZBX_CONTEXT_SCREEN_READER) will return false.

In order to avoid such, function _x() should be separated into two functions:

1. _x() should return translated string with unreplaced placeholders. Similar to function _().
2. _xs() should return translated string with replaced placeholders.Similar to function _s().