However you can still do it but it will be termed as customization
To change Header and Footer texts :
The messages for "'CA Clarity " PPM' and for 'Copyright 2014 CA Technologies. All rights reserved.' are included in :
%CLARITY_HOME%\resource\messages_xx.properties (xx is for all languages)
and
%CLARITY_HOME%\resource\messages.properties
Change: %CLARITY_HOME%\resource\messages_xx.properties (for all languages) and also change messages.properties union.ppm=CA Clarity™ PPMunion.copyRight=Copyright \u00A9 2014 CA Technologies. All rights reserved.
To change CA logo: Logo is in path: %CLARITY_HOME%\webroot\ui\evolution2\images\eMailLogo.gif
Hope this helps you.
Regards
Suman Pramanik