EllisLab/CodeIgniter — Issue #865: The standards are not followed by the developers
Author: vkeranov
Created: 2012-01-04 22:15:50+00:00
State: open

As I also described the problem in this forum topic:
http://codeigniter.com/forums/viewthread/207784/

Quote from the Codeigniter’s userguide:

Use of || is discouraged as its clarity on some output devices is low (looking like the number 11 for instance). && is preferred over AND but either are acceptable, and a space should always precede and follow !.

A recent commit on GitHub (from @ericbarnes, CI developer):

elseif ( ! $this->cur_page AND $CI->uri->segment($this->uri_segment) != $base_page)

And here is an interesting comment on GitHub (issue 811) by @philsturgeon (another CI developer) also:

Style Guide says it prefers AND over && generally.