Please provide option to define user tags (labels) for items (triggers, hosts, alerts, ...). They will be only metadata used for selecting - for example env = prod, tier = t1, name = db*. Tags will be useful for 3rd party tools - Grafana (API filtering by tag must be implemented as well).

It'll be awesome, if also agent can send tags with item value and zabbix-server will store them - for example fs util = 50% tags[fs=tmp] (see OpenTSDB metric tagging). LLD won't be needed, but more sophisticated UI will be required (querying with the tags).

It'll be useful for many products, where tagging is already used - see AWS, Kubernetes, ....

Ref:
http://docs.datadoghq.com/guides/tagging/
https://support.dataloop.io/hc/en-gb/articles/204704415-Overview
http://opentsdb.net/docs/build/html/user_guide/query/timeseries.html
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html
https://github.com/kubernetes/kubernetes/blob/release-1.1/docs/user-guide/labels.md