If you don't know the first thing about metadata, check out our series 'Metadata 101' for more information.

1. Smart metadata - The basics

2. Author, Title, Subtitle, Series fields

3. Category field

4. Embedding metadata within your book

(To be continued)

Metadata guidelines

Our partners take extra care when it comes to accepting or rejecting books to reach highest customer satisfaction. Nobody wants unhappy readers.

Our team follows the stores' guidelines when reviewing content to make sure that your books don't get flagged or rejected by the partner stores.

The following rules are excerpts from Amazon's and Apple Books' (iBooks) publishing guidelines.

Book title

The title field should contain only the actual title of your book as it appears on your book cover. Examples of items that are prohibited in the title field include but are not limited to:

• Unauthorized reference to other titles or authors
• Unauthorized reference to a trademarked term
• Reference to sales rank (e.g., "bestselling")
• Reference to advertisements or promotions (e.g., "free")
• Keywords

The title's language should be the same as the book's language.

Subtitle

Subtitles are subject to the same rules as titles.

Series

If your book is part of a series, enter the name of the series in the Series Name field. The series name will be displayed up after your book's title in parentheses.

The series name must adhere to the book title guidelines above.

Enter only the name of the series. Do not include the number in series (volume) or the title of the book. Enter the series number (volume) in the series number field as a single digit ("3" for the third book in a series, not "Book 3" or "Book 3 of 4"). If you include the correct series name, Amazon will automatically link your books.

Keywords

Keywords can be a word or a phrase. We recommend using phrases that are 2-3 words long.

Avoid keywords that are not accurate descriptors of your book's central storyline. Examples of items that are prohibited as keywords include but are not limited to: 

• Reference to other authors 
• Reference to books by other authors 
• Reference to sales rank (e.g., "bestselling")
• Reference to advertisements or promotions (e.g., "free")
• Reference to anything that is unrelated to your book's content.

Pen names

Your pen name cannot deceive readers. For example, if you are writing romance, you cannot write under the name Mr. Love. If your genre is self-help, please don't use John Doctor. (Unless it is your real name, of course.)

You are not allowed to enter any unnecessary information to the author field, e.g. you cannot enter the name of your publishing house as editor.

Descriptions

The language of the description should be the same as the language of the book.

If you would like to learn more about Amazon's guidelines, read more here.

Category

Although we recommend using niche categories, it is possible that some of the stores don't update their category list regularly. For example, iBooks and Google Play Books are currently using the 2016 BISAC category list. If your first (main) category is a new category (marked with * on the BISAC subject list), we might have to change the order of your categories or change your category to the closest available in order to get your book into Google Play or iBooks.