Charge Groups

To write a post on conflict-checking, I must first address charge groups. A charge group is simply a group of charges in similar locations and of similar visual weight on a device or badge. There are several different types of charge groups. All but one must lie in the central region of the shield.
Primary: The primary charge group is the most central thing in your armory.
Secondary: The secondary charge group is an accessory lying around the primary charge group.
Tertiary: The tertiary charge group lies completely on top of another charge or charge group.
Peripheral: The peripheral charge group is located on the edges of the field.
Overall: The overall charge group lies partially on another charge or charge group and partially on the field.
If lists of definitions aren't your thing, you can use this handy flow chart I made:

 

And here are some examples drawn at random from the Calontir populace armorial:
NOTE: If you can't see these pictures on your computer, use Ctrl+F to look up the names here: http://armorial.calontir.org/Pages/populace.htm I'll try to figure out what's going on and fix it later today.

Amelyn Pope: The axes are primaries because they are central to the design and lie completely on the field. The cauldrons are a tertiary charge group because they lie completely on top of the axes.

Jane Corwin: The triskelion of legs is the primary charge because it is central and carries the most visual weight. The bezants (yellow circles) are the secondary charge group because they lie around the primary charge and carry less visual weight.

Titus Decimius Alexander: The skull is the primary charge because it is central in the design. The embattled bordure is the a peripheral charge because it lies on the edge of the design.

Wolfger zum Grifen: The gryphon carries the most visual weight, but it doesn't lie completely on the field, so it can't be the primary charge. The pall it lies on top of is the primary charge. The gryphon is in an overall charge group.