Design of correspondence rules
A developer asks:
Do you have any suggestions for creation of correspondence rules (sometimes called templates)? We have a need for complex correspondence with multiple conditional variants. This lead us to the idea of using fragments (Rule-Corr-Fragment rule type) that are dynamically combined, but we want to avoid a jumbled mess of when's and includes.
As a best practice, use multiple correspondence templates rather than trying to manage the complexity within a single large template. Start by identifying the two or three major "personalities" that the correspondence can have, and then use those purposes to define the letters. Then look for opportunities to build includes that are shared across letters.
This approach should help to reduce the complexity and remove the need for excessive when directives.