What are naming conventions for MongoDB?

1. Keep'em short: Optimizing Storage of Small Objects, SERVER-863. Silly but true.

2. I guess pretty much the same rules that apply to relation databases should apply here. And after so many decades there is still no agreement whether RDBMS tables should be named singular or plural...

3. MongoDB speaks JavaScript, so utilize JS naming conventions of camelCase.

4. MongoDB official documentation mentions you may use underscores, also built-in identifier is named _id (but this may be be to indicate that _id is intended to be private, internal, never displayed or edited.

DATABASE

• camelCase
• append DB on the end of name
• make singular (collections are plural)

MongoDB states a nice example:

To select a database to use, in the mongo shell, issue the use <db> statement, as in the following example:

use myDB
use myNewDB

Content from: https://docs.mongodb.com/manual/core/databases-and-collections/#databases

COLLECTIONS

• Lowercase names: avoids case sensitivity issues, MongoDB collection names are case sensitive.

• Plural: more obvious to label a collection of something as the plural, e.g. "files" rather than "file"

• >No word separators: Avoids issues where different people (incorrectly) separate words (username <-> user_name, first_name <->
  firstname). This one is up for debate according to a few people
  around here but provided the argument is isolated to collection names I don't think it should be ;) If you find yourself improving the
  readability of your collection name by adding underscores or
  camelCasing your collection name is probably too long or should use
  periods as appropriate which is the standard for collection
  categorization.

• Dot notation for higher detail collections: Gives some indication to how collections are related. For example you can be reasonably sure you could delete "users.pagevisits" if you deleted "users", provided the people that designed the schema did a good job.

Content from: https://web.archive.org/web/20190313012313/http://www.tutespace.com/2016/03/schema-design-and-naming-conventions-in.html

For collections I'm following these suggested patterns until I find official MongoDB documentation.