Here; http://www.breakitdownblog.com/supported-values-for-suppresswarnings/. Note these are for main Java libraries; other APIs might have their own.
- all to suppress all warnings
- boxing to suppress warnings relative to boxing/unboxing operations
- cast to suppress warnings relative to cast operations
- dep-ann to suppress warnings relative to deprecated annotation
- deprecation to suppress warnings relative to deprecation
- fallthrough to suppress warnings relative to missing breaks in switch statements
- finally to suppress warnings relative to finally block that don’t return
- hiding to suppress warnings relative to locals that hide variable
- incomplete-switch to suppress warnings relative to missing entries in a switch statement (enum case)
- nls to suppress warnings relative to non-nls string literals
- null to suppress warnings relative to null analysis
- rawtypes to suppress warnings relative to un-specific types when using generics on class params
- restriction to suppress warnings relative to usage of discouraged or forbidden references
- serial to suppress warnings relative to missing serialVersionUID field for a serializable class
- static-access to suppress warnings relative to incorrect static access
- synthetic-access to suppress warnings relative to unoptimized access from inner classes
- unchecked to suppress warnings relative to unchecked operations
- unqualified-field-access to suppress warnings relative to field access unqualified
- unused to suppress warnings relative to unused code
- varargs to suppress warnings about unsafe usages of variable arguments (varargs) methods, in particular, those that contain non-reifiable arguments.