Module capabilities 

What each kind of server keeps, so that moving a task or a contact never loses something silently, and so that what a server cannot do shows greyed with its reason rather than hidden (docs/google.md).

A CalDAV or CardDAV server keeps everything Sioul writes. Google keeps less: its CalDAV holds events but no tasks and makes no calendar; its CardDAV writes vCard 3.0 and drops labels and birthdays without a year; Google Tasks keeps a title, notes, a status, a date and one level of steps.

Enums

Provider

Who keeps a collection.

Functions

contact_losses

What a contact’s card uses that an address book kept by provider would not keep: Google writes vCard 3.0, and drops labels, birthdays without a year, and what only vCard 4.0 has.

makes_collections

Whether a provider can make, rename and delete a calendar or an address book; Google Tasks makes task lists.

provider_of

Who keeps an account’s collections.

provider_of_collection

Who keeps a collection: a Google account’s task lists are Google Tasks’.

task_fields_lost

The task form’s fields a list kept by provider does not keep: shown greyed, with why. “steps” when the task is a step already (one level only).

task_losses

What a task uses that a list kept by provider would not keep, as words’ keys (“waits”, “repeat”…): what to say before moving it there.