What is the level of measurement / name of the scale of list-features? If you look at publications, you can have a dataset


title of publication
list of authors
number of pages
year of publication


The Level of measurement of "number of pages" is  interval scale, the year of publication is interval scale as well, the title is nominal. But what is the list of authors? Simply saying that it is nominal seems not to capture a major part of this attribute.
With a list such as this list of authors, the only representation which truly capture the semantics is a (long) list of boolean features, one for each possible author in the set. Ideally one would also pre-process the whole set of authors in order to match the different ways a name can be written, e.g. "J. Doe" = "John Doe" = "Doe, John".