Possible enumeration values:

NameValueDescription
Default

0

Use default functionality, usually meaning Add

Add

1

Add the modifier to the item

No

2

Remove this modifier from the item

Extra

4

An extra quantity of this modifier

Side

8

This modifier should be packaged as a side item

Light

16

A reduced quantity of the modifier

Everything

32

A special modifier which indicates that all available modifiers should be added

Plain

64

A special modifier which indicates that no modifiers should be added