Signal Box was developed for TS12 independently of, and prior to the existence of, N3V's Interlocking Tower development for TANE. Signal Box was released close to the release of TANE CE as a result of the long delay in the release of PLL, and not because of any co-development of the Signal Box rule and the Interlocking Tower rule. The Signal Box rule may have to be updated, along with other PLL assets, to work with the "full" version of TANE to be released in February.