Add entity tags restriction on pipeline cloud rules

src/content/docs/new-relic-control/pipeline-control/cloud-rules-api.mdx

@@ -55,6 +55,7 @@ Use cloud rules to target the following data types:
 * The limit on NRQL query length is **4096** characters. If it exceeds the length, the `INVALID_NRQL_TOO_LONG` error occurs. If you need to drop data based on a longer query that cannot be split, contact your [New Relic support](https://support.newrelic.com).
 * `JOIN` and [subqueries](/docs/query-your-data/nrql-new-relic-query-language/get-started/subqueries-in-nrql) are not supported.
 * You can provide a [`WHERE`](/docs/query-data/nrql-new-relic-query-language/getting-started/nrql-syntax-clauses-functions#sel-where) clause to select data with specific attributes.
+* You shouldn't use entity tags in a [`WHERE`](/docs/query-data/nrql-new-relic-query-language/getting-started/nrql-syntax-clauses-functions#sel-where) clause to drop data, because entity tags are fetched in a separate process and are not attributes of the MELT data evaluated by the pipeline cloud rule.
 * Features such as `LIMIT`, `TIMESERIES`, `COMPARE WITH`, `FACET`, and other clauses cannot be used.
 * `SINCE` and `UNTIL` are not supported. If you have time-specific rules (say, drop everything until a time in the future), use `WHERE timestamp < (epoch milliseconds in the future)`.
 * You can't use `SINCE` to drop historical data. Cloud rules only apply to data reported after the rule was created. If you need to delete data that has already been reported, refer to [Delete existing data](/docs/data-apis/manage-data/manage-data-retention/#deleting-data) or contact [New Relic support](https://support.newrelic.com).