How are these called? literals, captions, labels or properties?

Question

Instead of hardcoding text in the UI we use placeholders with keys which get replaced by the actual text. This also helps localisation of the application.

example Java properties file:

about=About
contact=Contact Us

These could also be found in the database or in XML files etc

How are these called?

• literals?
• captions?
• labels?
• properties?

I'm looking for a general and language agnostic term.

Edit: Adding all the suggested terms from answers:

• translatable strings
• resource strings
• Resource Properties
• localization
• Culture Variant UI Fields
• Locales
• Locales Strings
• messages
• message placeholders

I don't know why but it kind of saddens and confuses me that there isn't a single solid term to describe this thing. And in one way or another it exists in all languages and frameworks.

Answer 1

They are called resource strings, on many platforms, independent of what you are using them for. There isn't a general name for the individual resource strings related to localization. The general term for all of those resource strings together is called localization.