The following is taken from the Guide for Authors; it is the second paragraph under Part I. General Information. Introduction: coverage; approach for users, contributors; resources; other, future projects:
Like The Jepson Manual (TJM), the second edition of The Jepson Manual (TJM2) will be an illustrated guide to the identification of native and naturalized (see expanded definition in Glossary) vascular plants growing outside of cultivation in California. Any plant clearly demonstrating the potential to become naturalized outside of cultivation (e.g., commonly encountered garden escapes, waifs, or plants occurring spontaneously in crop fields, orchards, gardens, and urban settings) should be included in your treatment. Decisions about which of these to treat fully will be deferred until such time as we have a better idea about the ultimate size of the book. Any plants for which treatments are submitted under this guideline that are excluded because of space limitations will be included in the keys in TJM2, but otherwise will be fully treated only in the online accounts, as discussed at the end of this Introduction.
The paragraph above deals with what is to be included in treatments submitted by authors, as well as what ultimately will be included in TJM2, the difference between the two having to do with space considerations in the book. In preparing treatments, authors have been instructed to consult the Index to California Plant Names (ICPN), available at http://ucjeps.berkeley.edu/about_ICPN.html.
The following categories of occurrence in California are discussed in the paragraph from the Guide for Authors, above, and correspond to the indicated Current Status Categories in ICPN. Thus, in consulting ICPN, names for taxa in the indicated Current Status Categories should be included. Cases in which placement in these categories is indicated in ICPN to be tentative are to be resolved by the authors in preparing their treatments for TJM2.
In addition, as in TJM, plants that are extirpated from part or all of California (JFP-6) or that are extinct (JFP-7) are to be included in your treatments, as are taxonomically recognized and/or fertile hybrids, using either the hybrid (JFP-10) or non-hybrid (JFP-10a) forms of the names involved.