Merge pull request #5812 from jeffalder/patch-2

SINCE, UNTIL, and LIMIT not supported

src/content/docs/data-apis/manage-data/drop-data-using-nerdgraph.mdx

@@ -82,7 +82,9 @@ There are two ways to drop data:
 
 ## NRQL restrictions [#restrictions]
 
-Not all NRQL clauses make sense for generating drop rules. 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. Other features such as `TIMESERIES`, `COMPARE WITH`, `FACET`, and other clauses cannot be used.
+Not all NRQL clauses make sense for generating drop rules. 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. Other features such as `LIMIT`, `TIMESERIES`, `COMPARE WITH`, `FACET`, and other clauses cannot be used.
+
+`SINCE` and `UNTIL` are not supported in drop rules. If you have time-specific rules (say, drop everything until a time in the future), use `WHERE timestamp < (epoch milliseconds in the future)`. You also can't use `SINCE` to drop historical data: NRQL drop rules only apply to data reported after the drop rule was created. If you need to delete data that has already been reported, contact your New Relic representative.
 
 The two action types have these restrictions: