numass-framework/site/content/docs/shards/envelopes/envelope_description.md

content_type	title	chapter	ordering	label	published
doc_shard	Envelope description	envelope	20	envelope_description	true

Interpretation of envelope contents is basically left for user, but for convenience purposes there is convention for envelope description encoded inside meta block.

The envelope description is placed into hidden @envelope meta node. The description could contain following values:

• @envelope.type (STRING): Type of the envelope content
• @envelope.dataType (STRING): Type of the envelope data
• @envelope.description (STRING): Description of the envelope content
• @envelope.time (TIME): Time of envelope creation

Both envelope type and data type are supposed to be presented in reversed Internet domain name like java packages.