From the PDF Introduction
A Monster Manual (D&D 3.5e) v3.5 Web Enhancement
The organization entries in the Monster Manual give some indication of what kinds of groupings various creatures might form. These entries are intended as examples to get you thinking about how the creatures live and act from day to day.
When you sit down to create an adventure or encounter featuring a group of creatures in their lair, you can use the organization entry (along with other elements of the creature description) as a creative springboard.
The sample lair presented here is an outpost used by a hobgoblin war party. It also embodies some elements of a hobgoblin tribal lair.