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Velocity belongs to Apache and they have a very useful page that describes the fundamental syntax and semantics of the language. See their user guide for more information about the language itself.

Notification aggregation

There can be multiple recipients for a single notification. The Template Set is run once for each recipient and identical notifications are aggregated together so that a single email is sent out with all of the related recipients included as one, instead of lots of individual identical emails with one for each recipient.

Macro import structure

We use a multi-tier system where the more general tiers are imported into the more specific tiers, thus making all of the macros in the general tier available in the more specific tiers.

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