The fifth (and final!) Cinderella tale type in Cinderella Tales From Around the World is ATU 510B and 923 Love Like Salt.
ATU 510B and 923 Love Like Salt
Love Like Salt, while deceptively simple, can be more complicated in its classification under the ATU system with many tales often classified as both ATU 510B and ATU 923 depending on the events in the often short tale. Some of the earliest documented appearances of this tale include Geoffrey of Monmouth’s Historia Regum Britanniae from the 12th century and Shakespeare’s King Lear circa 1608.
A wealthy man, usually a king, asks his three daughters how much they love him. The two eldest answer with over effusive descriptions, comparing their love to precious items which also reveals their greedy natures. The third daughter states that she loves him as much as she loves salt. The other daughters are richly rewarded for their flatteries. Offended by the comparison to a common item, he banishes the youngest daughter from his kingdom or even orders her put to death, but she escapes. She finds work as a servant in another realm. Through various events similar to those in other ATU 510B variants, the prince falls in love with her and marries her. The father is invited to the wedding feast where his meal is specially prepared without any salt. He soon realizes the importance and preciousness of salt and bemoans the loss of his daughter. She is revealed to him and all is forgiven. When a magic helper as well as an identifying object appear in the tale, it is classified as ATU 510B. A lack of those elements usually makes it a straightforward ATU 923 tale.
This is the most confusing of the tale types. Not about it being a Cinderella variant but that there are two ATU numbers for this type of tale and delineating between them ended up being more than I wanted to do so I included both ATU 510B and 923 tales. This type of tale tends to be short. Unless you're Shakespeare and have written an entire play based on the plot devices....