Reference: DropRateProfile.txt

Purpose

Contains the drop rate settings for randomly generated items.

File Format

Table file. Tab separated values.
Comment character: semicolon (;)
First line is always ignored (assumed as header).

Table Columns

DropRateTable The name of the profile. There are two built-in profiles which may be customized here (standard, instance). The defaults are explained below, but they can be modified in the file. Specific zones or dungeon modes can be assigned new custom entries defined here.
QL0xxx ... QL6xxx Drop rate for each corresponding mQualityLevel, from 0 to 6. Drop rates are expressed as a denominator. For example, a value of 100 means the drop chance is 1/100, or 1%. Use a value of 0 to disallow drops.
QL0xxxL ... QL6xxxL Minimum creature level required to drop the corresponding mQualityLevel. Use -1 to disallow drops.
QL0xxxF ... QL6xxxF Restrict this corresponding mQualityLevel from dropping only from particular types of creature rarities, or normal or named mobs. Use a sequence of the following characters. Any mob types not explicitly written will not qualify, except when using asterisks to automatically include all types. Lowercase letters mean only named mobs. Uppercase letters mean both named mobs and regular mobs.

* : All mobs of any rarity, named or not.
N : All normal mobs.
n : Only named normal mobs.
H : All heroics.
h : Only named heroics.
E : All epics.
e : Only named epics.
L : All legendary mobs.
l : Only named legendary mobs.

Note that most epic mobs are named. Legendary mobs generally don't exist, but controls are provided here for completeness.

Defaults

Two profiles have default configurations: {standard, instance}. The drop rates here are the default configurations.

standard is used for all non-dungeon instances, unless an override is set.

Drop rates:
Uncommon: 1 in 25, all mobs level 1 or higher.
Rare: 1 in 125, all mobs level 15 or higher.
Epic: 1 in 625, all mobs level 25 or higher.
Legendary: Doesn't drop.

instance is used for all dungeon instances, unless an override is set.

Drop rates:
Uncommon: 1 in 25
Rare: 1 in 100
Epic: 1 in 500
Legendary: 1 in 4000, all mobs level 45 or higher.