ConVarFlags
#
FCVAR_UNREGISTERED = 1

If this is set, the convar will become anonymous and won't show up in the 'find' results.
FCVAR_DEVELOPMENTONLY = 2
FCVAR_HIDDEN = 16
FCVAR_PROTECTED = 32

Makes the ConVar value hidden from all clients (for example sv_password). Reported as "prot" by cvarlist.
FCVAR_SPONLY = 64

Executing the command or changing the ConVar is only allowed in singleplayer. Reported as "sp" by cvarlist.
FCVAR_ARCHIVE = 128

Save the ConVar value into config.cfg. Reported as "a" by cvarlist, except Lua ConVars.
FCVAR_NOTIFY = 256

For serverside ConVars, notifies all players with blue chat text when the value gets changed. Reported as "nf" by cvarlist.
FCVAR_USERINFO = 512

For clientside commands, sends the value to the server. Reported as "user" by cvarlist.
FCVAR_PRINTABLEONLY = 1024

Forces the ConVar to only have printable characters (no control characters). Reported as "print" by cvarlist.
FCVAR_UNLOGGED = 2048

Don't log the ConVar changes to console/log files/users. Reported as "log" by cvarlist.
FCVAR_NEVER_AS_STRING = 4096

Tells the engine to never print this variable as a string since it contains control sequences. Reported as "numeric" by cvarlist.
FCVAR_REPLICATED = 8192

For serverside ConVars, it will send its value to all clients. The ConVar with the same name must also exist on the client! Reported as "rep" by cvarlist.
FCVAR_CHEAT = 16384

Requires sv_cheats to be enabled to change the ConVar or run the command. Reported as "cheat" by cvarlist.
FCVAR_SS = 32768
FCVAR_DEMO = 65536

Force the ConVar to be recorded by demo recordings. Reported as "demo" by cvarlist.
FCVAR_DONTRECORD = 131072

Opposite of FCVAR_DEMO, ensures the ConVar is not recorded in demos. Reported as "norecord" by cvarlist.
FCVAR_NOT_CONNECTED = 4194304

Makes the ConVar not changeable while connected to a server or in singleplayer.
FCVAR_VCONSOLE_SET_FOCUS = 1073741824