If you’re writing historical, multicultural, or both, it’s important to include a glossary, and possibly an author’s note or other appendices. Your readers who are unfamiliar with the culture, language, and/or era will thank you.
For Jakob’s story, whose release is planned for Friday, I decided to include three sections after the main text ended. I have a list of the sources I consulted, a glossary, and some notes explaining a few things, like how Dutch women are traditionally Lucy Stoners (i.e., they keep their birth surnames after marriage).
While doing my last edit/polishing of the book, I took note of each Dutch or Hebrew term which appeared, and jumped to the glossary in progress to add the words in alphabetical order. My last major thing left to do is finish writing definitions for all the words or concepts. I also included the names of some of the Amsterdam streets and neighbourhoods.
Some of these things are explained in the text, or otherwise made clear through context, but I thought it was a nice touch to have them all defined in one place anyway. Even though I know a number of the people in my community will be reading the book, and therefore know what these Hebrew words mean, I can’t arrogantly assume everyone who reads my book will be Jewish. I care about my readers of all faiths.
I’ve studied lots of world religions, and probably know quite a bit more about Hinduism, Buddhism, certain Christian denominations (particularly Roman Catholicism, Eastern Orthodoxy, and Mormonism), Jainism, Islam, Sikhism, Wicca, and Zoroastrianism than the average non-member. (That was the whole reason I recognised the blatantly Mormon language in Beatrice Sparks’s books as yet another clue of her authorship of these “real teen diaries.” I honestly would have more respect for her if she’d just been honest and made her characters Mormon like she was, instead of pretending they were other denominations!) But I know I’m unusual for being so well-versed in so many other religions.
I’m currently revisiting Sydney Taylor’s More of All-of-a-Kind Family, and there are a number of really awkward, infodumpy passages or dialogues that slow the story down by stopping to explain what certain holidays or concepts are. The dialogues are really “As you know, Bob.” That problem is easily solved by a glossary or appendix.
I have much larger glossaries for my Russian historicals. I have sections for foreign words broken down into categories like vulgarities and insults, food, historical references, family relations, terms of endearment, and miscellaneous. Since I’m dealing with prominent characters and words of a number of different backgrounds in the current third book, I indicate in parentheses if a word is Russian, Estonian, Georgian, Armenian, Persian, Belarusian, Ukrainian, etc.
For Little Ragdoll, I went all out with appendices, covering things like real places and streets in Manhattan which were featured; the vintage toys and games mentioned; a chronological listing of all the books, songs, and albums which were featured or mentioned; and the characters’ names’ popularity in their years of birth. Finishing those appendices is the last major thing I have left to do with that book.
If you’ve played with a historical timeline or event to allow for more drama or work better with your story’s timeline, or if a big part of your story revolves around something that would’ve been an unusual occurrence in real life, it’s important to mention that in a note. Historical purists will probably still get their knickers in a knot, but at least you’ve acknowledged something was slightly altered for the purposes of storytelling.
In the notes for my first Russian historical, for example, I explain that the titles Mr. and Mrs. are very rarely used in Russian, but that I retained them as a way of distinguishing the older characters from the younger characters. It was my one major concession to Western naming sensibilities.
Finally, I like to maintain a list of characters, generally in the order they appear, with the names of main and important secondary characters bolded. I include birthdates when known, nicknames or titles in parentheses, and a brief identification of who they are. If a character later changes his or her name, I list him or her by the name with which s/he first appears. As an animal-lover, I also include the pet characters.