* It's a specific brand or product name: There might be a company or manufacturer using "Regiform" for a particular type of box. To clarify, you might need to provide more context, such as where you encountered this term (e.g., a website, a store, a conversation).
* It's a misspelling: Perhaps the term is actually "register form boxes" or "registration form boxes," referring to boxes used for holding registration forms.
* It's a specialized term: It could be a term specific to a particular industry or field. For example, "Regiform" might refer to a type of box used in the legal profession or in archives.
To get a more accurate answer, please provide more context about where you encountered the term "regiform boxes."