According to Roman, the point of having field converters is "that you can open old dialogs in new apps, not use old fields in a new app descriptor". In light of this, have another close look at https://documentation.magnolia-cms.com/display/DOCS62/Field+converters and check if that's already clear or if there's anything at odds with that statement.

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Roman: "Looking at https://documentation.magnolia-cms.com/display/DOCS62/Field+converters#Fieldconverters-Examplefieldconverter, it explains the use in dialogs already. We might want to emphasize the statement about the app descriptor though."

Ashraf: "I think what's confusing is that they are called "field converters", but they are used at the dialog level. We also need to make clear that converters are used for opening old dialogs/fields in new apps."

Roman: "Dialogs consist of fields, so to convert a dialog, we have to covert all fields inside the dialog."

Ashraf: "Yes, but the name could be misleading. It's about compatibility at the dialog level, not the field level. And of course that trickles down to the field level since dialogs contain fields."

Roman: "If most users don't use it programmatically, then "dialog converters" could be a better title."