The Spirit Realm

I am currently wielding the 1H Convortium sword (Fallen Leviathan's Runic Hatchet) that proc Blessed Rune IV.
My Blessed Serilis Prayer Shawl also proc a Rune (Blessed Defending Courage of Brell).
I have max AAs of Mystical Attuning (additional buff slots) .

My question/concern is this:
If either or both Runes procced when all the buff slots are filled with other buffs, will I gain the benefits of Rune even though there are no more buff slots available for the Rune icons ?

I would rather trade my Blessed Serilis Prayer Shawl to the melee version (mine is a tank version), which has a proc of direct healing (hence, no buff slot required) and added damage bonus, if the Rune proc requires a buff slot available in order for me to gain the benefit. Most of the times, all my buff slots are filled whether I am in group or raid. Thanks in advance for your help.

The prayer shawl rune proc under the song window as I remember and to me, Having a rune proc > having say a attack clicky so I drop things like levi or attack clickies for extra space for rune procs. But it does also depend on the role you play...if you want more ae aggro, go rune proc, if self healing more fits the bill try the melee version.

I confirmed that both Rune procs go to the regular buff windows. So my question still remain : Does Rune proc must have an available buff slot for its icon to show in order for me to gain the benefit ?

yes

Thanks for answering my question. I'm surprised that the rune proc from the 7th shawl took up a buff slot in the regular buff window. I think it should be in the short buff duration window since the buff only lasted for 60 seconds (10 ticks) according to

http://www.raidloot.com/Spells.aspx?id=20546

I'm wondering if it was intentional or mistaken on SoE's part. The proc would be way more useful, to me at least, if it were placed in the short duration buff window.