Bow add-ons

I've got several gold bows maxed out. My fav. bow has 15% dam. 33% poison duration, (and another stat I can't remember cuz i'm at work). My question is, I see people selling bow strings and grips. Aparently the grip is an addon? So if I buy the grip I can apply it to my gold bow for additional properties? (Grip is usually +health?) Just a little confused on what and when these strings/grips can be added to. Any advice would help me out a lot. Thanks

The name of a bow is often something along the line of ACTIONING Bow of SOMETHING. ACTIONING is a prefix, controled by a Bow String upgrade, while SOMETHING is a suffix controlled by a Bow Grip upgrade. Applying an upgrade to a bow that already has a prefix/suffix will replace the existing one.

And I'm not sure of it, but I recall reading that any health penalties will stay around and stack with the new prefix/suffix, rather than be 'replaced'.

For more information, I recommend the following:
http://gw.gamewikis.org/wiki/Bow#Upgrades_and_Modifiers
http://hahnsoo.100free.com/Guild_Wars_ranger_guide.html

~Salad