ExtJS 4 Naming Conventions

Official, I'm not sure, but in my opinion..

• Root namespaces and constructors are UpperCamelCase
• Sub-namespaces, styles, events and xtypes are lowercase
• Methods, attributes and variables are lowerCamelCase

There absolutely is an official stance. It is outline in section 2 of the Class System guide. Here is the link: https://docs.sencha.com/extjs/7.2.0/guides/core_concepts/classes.html#core_concepts--classes-_naming_conventions