Primary prim?

I noticed some people are saying that for various reasons, you shouldn't make certain prims your primary prim in a linked object. I didn't even know it was possible to choose this. how is it done?

The last prim you select in a group will be the 'primary' prim, if you will. If you're just dragging over a group of prims, just deselect and reselect the prim you want to be the primary, link, and voila.

I've never heard that before. What have they been talking about not making root (primary) prim?

In scripting, it is good for certain prims to be "primary", such as if the code has llSetColor instead of llSetLinkColor. (This is bad code btw, all the commands should be llSetLinkColor just in case.)

Also, a script that changes textures can't do it on a different prim directly without use of a second script on the affected prim. So the parent prim has to be the one whose texture is to be changed if you want to have fewer scripts running.

Choosing a wonky positioned prim might be of some concern if its some attachment. A prim furry avatars head for example. You'd choose a prim along the line of symmetry, maybe the nose for example, instead of an ear. Simply because it makes it much easier to adjust after its attached.