Manual:Conformance Testing Mode
This mode allows you to test wireless channels outside the default scan-list and/or regulatory domain. This mode should only be used in controlled environments, or if you have a special permission to use it.
Before v4.3 this was called Custom Frequency Upgrade, or Superchannel. Since RouterOS v4.3 it is called Conformance Testing Mode and is available without special key upgrades for all installations.
Please note that the Conformance Testing Mode is available free of charge since v4.3.
License upgrade purchase is only needed if you intend to use older versions, where this mode was called Superchannel.