I’m are happy to announce that Acumatica team has updated descriptions of all Acumatica Framework core classes and methods as part of new Acumatica Development Reference Library. All of them are located in one place now: Acumatica xRP Reference Guide
The content is collected directly from the Acumatica code and presented in a clear and concise way. You can easily find the needed information and code examples, which you can use in your customization and custom solutions.
Please let me know if you have any questions or other suggestions!