diff --git a/NEWS.md b/NEWS.md
index 9582060a5e..f1240fef2c 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -34,7 +34,7 @@
     
 8. `DT[..., .SDcols=]` now accepts `patterns()`; e.g. `DT[..., .SDcols=patterns("^V")]`, for filtering columns according to a pattern (as in `melt.data.table`), [#1878](https://github.com/Rdatatable/data.table/issues/1878). Thanks to many people for pushing for this and @MichaelChirico for ultimately filing the PR. See `?data.table` for full details and examples.
 
-9. New `frollmean` has been added to calculate _rolling mean_. Function name and arguments are experimental. Related to [#2778](https://github.com/Rdatatable/data.table/issues/2778) (and [#624](https://github.com/Rdatatable/data.table/issues/624), [#626](https://github.com/Rdatatable/data.table/issues/626), [#1855](https://github.com/Rdatatable/data.table/issues/1855)). Other rolling statistics will follow.
+9. New `frollmean` has been added to calculate _rolling mean_, see `?froll` for documentation. Function name and arguments are experimental. Related to [#2778](https://github.com/Rdatatable/data.table/issues/2778) (and [#624](https://github.com/Rdatatable/data.table/issues/624), [#626](https://github.com/Rdatatable/data.table/issues/626), [#1855](https://github.com/Rdatatable/data.table/issues/1855)). Other rolling statistics will follow.
 
 10. `setDTthreads()` gains `restore_after_fork=`, [#2885](https://github.com/Rdatatable/data.table/issues/2885). The default `NULL` leaves the internal option unchanged which by default is `TRUE`. `data.table` has always switched to single-threaded mode on fork. It used to restore multi-threading after a fork too but problems were reported on Mac and Intel OpenMP library (see 1.10.4 notes below). We are trying again thanks to suggestions and success reported by Kun Ren and Mark Klik in package `fst`. If you experience problems will multi threading after a fork, please restart R and call `setDTthreads(restore_after_fork=FALSE)`.
 
diff --git a/man/froll.Rd b/man/froll.Rd
index 9c2ed27781..a8180e59b2 100644
--- a/man/froll.Rd
+++ b/man/froll.Rd
@@ -8,7 +8,7 @@
 \alias{frollsum}
 \title{Rolling functions}
 \description{
-  Fast rolling functions to calculate aggregates on sliding window.
+  Fast rolling functions to calculate aggregates on sliding window. Function name and arguments are experimental.
 }
 
 \usage{