This is where my HPB (History Patrol Bible) comes in handy. I have a notebook that I started, divided into these sections:
- when characters were born, died, reincarnated, then met each other in their first and second lives
- facts about the History Patrol, future politics
- Rules: information mentioned by characters when discussing the patrol (for example, a shapeshifter cannot be in human form until he/she obtains penance or grants forgiveness)
- Vocabulary: what terms are used, what is capitalized, what context is used for terms (“Companion” vs “companion”; Recall Beacon, etc.)
- Timeline: future history: what wars occurred prior to the Great Intervention, what kinds of events shaped future humankind, etc.
- Brain dump: this is background information that would probably never get to the readers but which would help me articulate why certain rules were in place, why characters acted as they did, etc.
Once I had the notebook started, it was relatively simple to keep it updated. As I wrote books, I added facts or double-checked facts I was using.
For each book, I also had a story notebook. I do this for any novel I write: I get a small notebook and paste in it any facts, pictures, ideas, thoughts and research needed. These books get pretty complex for the History Patrol because not only is it reincarnation, there’s time travel involved, so I have to do a lot of research about the time period and the place where the books take place.
The first book, Penance, takes place in 1876. The second, Vengeance is current day (first-person male POV about a Companion who is trapped in the 20Compassion, is set in 1934.
Added to the complexities of the fictional culture, my initial publisher (Cerridwen) instituted some tricky typographic conventions in the first book. They didn’t want telepathic thought in italics, so I had to come up with a way to show telepathy using brackets [ ] and braces { }. Luckily they dropped this by the time I worked on the second book.
It got very, very convoluted. Luckily, that all changed for the 2nd and 3rd books, so I didn't have to worry about it any more. Then the rights were returned to me and I didn't worry about it at all!