stacking how

I got some elemtalist headgear, 2 all seeing eyes , atrribute bonus enrgy+1, as i thought u could stack one on the other, but it wont. How do you stack?
Thanks

I dont believe you can stack any armor

You can only wear one bodytype of armor at the same type: one head piece, one chest piece, one arms piece, one legs piece and one feet piece. So you can't wear two all seeing eyes (head pieces) at the same time.

stacking refers to the effect of runes
i recommend reading the wiki section on runes and insignias for armor
someone will post a link to it here im sure soon

^---- soon-ish

Wiki
Runes
Insignia

if you add a +1 energy rune to your energy head gear it stack making it +2 energy attribute (highest without runes and headgears are 12, making it 14).

if you add another +1 energy rune to any of your other armours you still only get +2 energy attribute. (note you still can add said rune to your other armours, but the benefit isn't available)

same with other head gears of other attributes and other professions. (thats for head gear)

other runes, one that i can remember is the +3 absorb for warrior has 2 version, one is stackable one is unstackable, and you can put as many as you like on all your armours piece, but you will have to forfeit other runes.

What?

I feel dizzy

I think he means Knight's Insignia and Runes of Absorption.

Knight's Insignia only apply to the armor piece they are on, so for full effect (-3 physical dmg always) you need to put one on every piece.

Runes of Absorption are non-stacking, putting a minor and superior rune on your armor will still only give you the effect of the superior rune, not both.

can u put the rune of any profession on your armour?

No, you can only use runes for your Primary Profession, and those that don't require a profession (vigor, vitae etc.)

Have a read of this page here: http://wiki.guildwars.com/wiki/Rune