This command controls the tracking of the keys in the next command executed by
the connection, when tracking is enabled in `OPTIN` or `OPTOUT` mode. Please
check the [client side caching documentation](/topics/client-side-caching) for
background informations.

When tracking is enabled Redis, using the `CLIENT TRACKING` command, it is
possible to specify the `OPTIN` or `OPTOUT` options, so that keys in read only
commands are not automatically remembered by the server to be invalidated later.
When we are in `OPTIN` mode, we can enable the tracking of the keys in the next
command by calling `CLIENT CACHING yes` immediately before it. Similarly when we
are in `OPTOUT` mode, and keys are normally tracked, we can avoid the keys in
the next command to be tracked using `CLIENT CACHING no`.

Basically the command sets a state in the connection, that is valid only for the
next command execution, that will modify the behavior of client tracking.

@return

@simple-string-reply: `OK` or an error if the argument is not yes or no.