As you may know, there is an option in RIFT for self-cast: Settings > Interface > Combat > Auto Self-Cast
If you enable the option, when you have an enemy targeted and cast a beneficial spell that can be cast on other players, that spell is cast on you, but your enemy remains as your target. This is the behavior I typically want in PVP.
However, that UI option does not work if you are using a macro!
Take for example the following Cleric macro which is intended for self-healing:
#show Healing Breath suppressmacrofailure cast Healing Breath cast Doctrine of Bliss cast Healing Grace
If you have an enemy targeted and cast that macro to heal yourself, the target in the UI switches from your enemy to you if the spell cast is Healing Breath or Healing Grace, because those spells can be cast on other players. This can be really annoying to deal with, especially in group / raid fighting when you want to keep the same enemy targeted.
There is a simple fix to get Auto Self-Cast working for macros. Simply add the @self parameter for any spells that you want to be cast on yourself without causing a target switch:
#show Healing Breath suppressmacrofailures cast @self Healing Breath cast Doctrine of Bliss cast @self Healing Grace
Taugrim's MMO Blog 
Why not make the macro work like this:
#show Healing Breath
suppressmacrofailures
cast Healing Breath
cast [alt] @self Healing Breath
cast Glry of the Chosen
cast [alt] @self Glory of the Chosen
cast Doctrine of Bliss
cast [alt] @self Doctrine of Bliss
That way you’re given the option of self cast or target cast by hitting alt when clicking the macro.
Nevermind my spelling.
Sure you can do that. But you have a bug in your macro: the [alt] entries would need to come before the non-alt entries.
E.g.
cast [alt] @self Healing Breath
cast Healing Breath
Hey again,
I read somewhere on the forums and have now confirmed in my macros that using @mouseoverui will:
1) Heal the person you are moused over in the UI
2) If you don’t have someone moused over, it will heal the person you have targeted
3) If neither of the above are satisfied, then it will heal yourself
If you have an enemy targeted, it will stay on target.
I do not use cast on target of target. I want to place my heal on who I want and I find pvp targets change a lot.
Robinton
That’s my understanding as well, and I don’t use cast on target of target for the same reason. That option would be useful in PVE though.