Template:Citation Style documentation/deprecated
In addition to the above list(s) of deprecated and removed parameters, all non-hyphenated aliases of parameters with hyphens are discouraged to be used in citation templates and are kept only for legacy support. They are subject to becoming deprecated and unsupported in the future as well. To streamline the appearance and improve consistency across the project, these variants should no longer be used when adding parameters to citation templates. Instead, select the hyphenated parameter variants and also consider switching other non-hyphenated parameters, which may be present in a citation already, to their hyphenated equivalents at the same time.