This template should be placed at the top of entries for terms that are not attested, but are believed to exist based on comparative linguistics. All such entries should be in the Reconstruction namespace.
It invokes Module:reconstruction to check headers on the page. The categories that may be added are Category:Proto-Indo-European entries with more than one part of speech and subcategories of Category:Entries without References header by language and Category:Entries without References or Further reading header by language.