What gets automatically added to a property file for translation?
I'm guessing a label text would make it. What if you just typed text in directly without using a label control? Will that make it into a properties file?
Yes, the text you typed in would go into a .properties file.
Both in-line text, and the values of properties that were defined as localizable, are extracted to the property files.
For further details see the document "How to use the localization options for XPages
", Section 5: Extracted values