ContentTweaker extends the command palette provided by CraftTweaker.
To access these commands you do the same as you do for CraftTweaker commands, you use the /crafttweaker prefix

List of ContentTweaker Commands

Link to list-of-contenttweaker-commands

Usage:

/crafttweaker blockmaterial

/ct blockmaterial

Description:

Outputs a list of all the block materials in the game to the crafttweaker.log file.

Usage:

/crafttweaker creativetab

/ct creativetab

Description:

Outputs a list of all the creative tabs in the game to the crafttweaker.log file.

Usage:

/crafttweaker soundevent

/ct soundevent

Description:

Outputs a list of all the sound events in the game to the crafttweaker.log file.

Usage:

/crafttweaker soundtype

/ct soundtype

Description:

Outputs a list of all the sound types in the game to the crafttweaker.log file.