The name of the serials that appear here and appear on some DVD releases never show on screen at any time. Creator Peter Hammond has also confirmed that the names were not part of production documents and the episodes were only given numbers. The names also don't appear on VHS releases of the series. It is believed that the serial names were given by fanzine authors to make discussion of series easier, but this has not been able to be confirmed.
The original idea was for Sapphire's powers to be signified by a throbbing blue vein on her forehead, this was ultimately replaced with her eyes turning a vivid shade of blue.
Sapphire: The first nursery rhyme derives from the time of the plague; and the second one which Rob was made to say also has historical reference. It refers back to the Parliamentary Wars.