Add a property cto:textIncipit to cto:Item?

Could we add a property cto:textIncipit to cto:Item? We noticed that letter editions, like music editions, provide a brief opening in their feeds to cater to the search behaviour of researchers, i.e. knowing the opening line of a letter more than its title or ID.

We currently have a cto:Incipit, but this entity may only be used for musical works. Hence the suggested new property.