The 'Signature - Royals' line is officially nameless, but referred to as 'Signature' or 'Basic' by the fans. In order to stay consistent with the Monster High Wiki, the Ever After High Wiki favors the 'Signature' designation. The Ever After High Wiki also opts to consider the encompassing 'Signature' series split between 'Signature - Royals' and 'Signature - Rebels' as per the assortment setup. In the shopping section of the everafterhigh website the signature dolls are sorted into the collection called "Originals."
The 'Signature - Royals' series does not have specific fiction to support, as the dolls represent the characters in their default fashion. Nearly every piece of fiction to feature the characters has them wearing (or can be assumed to have them wearing) their 'Signature - Royals' fashion.
Lizzie Hearts's 'Signature - Royals' doll was originally announced for December of 2013 and her profile on the website, the release of which precedes a doll release, has an odd history of first being uploaded in English exclusively to the Spanish portion of it before being uploaded in the other versions nearly a month later. It thus appears there were several communication errors or last-minute changes regarding Lizzie's release date.
In Late 2014, problems occurred in the manufacturing process of the 'Signature' dolls, which is why no new dolls joined the lineup between July 2014 and Early 2015.