No hard rules decide how to spell invented compound words.

Evidence

A compound word joins two or more words to express a single thing. Frequently used compounds become a permanent part of the language , but many others are writers’ temporary constructions that will probably never see widespread use . These latter constructions can’t be found in any dictionary, so how do we know whether to spell them as separate words (“open”), hyphenated, or as a single word (“closed”)? A few principles can guide us, but there are no hard-and-fast rules. — Bryan A. Garner, Jeff Newman, Tiger Jackson, The Redbook, 214

Categorization

• DEFINE: Introduces the open/hyphenated/closed spelling framework for compounds and the ‘temporary constructions’ concept.