diff --git a/README.md b/README.md
index de5fcd1cb7..c8f372521c 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ Cluster version is available [here](https://github.com/VictoriaMetrics/VictoriaM
 ## Prominent features
 
 * Supports [Prometheus querying API](https://prometheus.io/docs/prometheus/latest/querying/api/), so it can be used as Prometheus drop-in replacement in Grafana.
-  Additionally, VictoriaMetrics extends PromQL with opt-in [useful features](https://github.com/VictoriaMetrics/VictoriaMetrics/wiki/ExtendedPromQL).
+  VictoriaMetrics implements [MetricsQL](https://github.com/VictoriaMetrics/VictoriaMetrics/wiki/ExtendedPromQL) query language, which is inspired by PromQL.
 * Supports global query view. Multiple Prometheus instances may write data into VictoriaMetrics. Later this data may be used in a single query.
 * High performance and good scalability for both [inserts](https://medium.com/@valyala/high-cardinality-tsdb-benchmarks-victoriametrics-vs-timescaledb-vs-influxdb-13e6ee64dd6b)
   and [selects](https://medium.com/@valyala/when-size-matters-benchmarking-victoriametrics-vs-timescale-and-influxdb-6035811952d4).
diff --git a/docs/ExtendedPromQL.md b/docs/ExtendedPromQL.md
index e9ac32fb64..81e9ed4712 100644
--- a/docs/ExtendedPromQL.md
+++ b/docs/ExtendedPromQL.md
@@ -1,9 +1,24 @@
-# PromQL extensions
+# MetricsQL
 
-VictoriaMetrics supports [standard PromQL](https://prometheus.io/docs/prometheus/latest/querying/basics/)
-including [subqueries](https://prometheus.io/blog/2019/01/28/subquery-support/).
-Additionally it supports useful extensions mentioned below.
-Try these extensions on [an editable Grafana dashboard](http://play-grafana.victoriametrics.com:3000/d/4ome8yJmz/node-exporter-on-victoriametrics-demo).
+VictoriaMetrics implements MetricsQL - query language inspired by [PromQL](https://prometheus.io/docs/prometheus/latest/querying/basics/).
+It is backwards compatible with PromQL, so Grafana dashboards backed by Prometheus datasource should work the same after switching from Prometheus to VictoriaMetrics.
+
+The following functionality is implemented differently in MetricsQL comparing to PromQL in order to improve user experience:
+* MetricsQL takes into account the previous point before the window in square brackets for range functions such as `rate` and `increase`.
+  It also doesn't extrapolate range function results. This addresses [this issue from Prometheus](https://github.com/prometheus/prometheus/issues/3746).
+* MetricsQL returns the expected non-empty responses for requests with `step` values smaller than scrape interval. This addresses [this issue from Grafana](https://github.com/grafana/grafana/issues/11451).
+* MetricsQL treats `scalar` type the same as `instant vector` without labels, since users usually don't feel the difference between these types.
+  See [the corresponding Prometheus docs](https://prometheus.io/docs/prometheus/latest/querying/basics/#expression-language-data-types) for details.
+
+Other PromQL functionality should work the same in MetricsQL. [File an issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues)
+if you notice discrepancies between PromQL and MetricsQL results other than mentioned above.
+
+MetricsQL provides additional functionality mentioned below, which is aimed towards solving practical cases.
+Feel free [filing a feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues) if you think MetricsQL misses certain useful functionality.
+
+*Note that the functionality mentioned below doesn't work in PromQL, so it is impossible switching back to Prometheus after you start using it.*
+
+This functionality can be tried at [an editable Grafana dashboard](http://play-grafana.victoriametrics.com:3000/d/4ome8yJmz/node-exporter-on-victoriametrics-demo).
 
 - [`WITH` templates](https://play.victoriametrics.com/promql/expand-with-exprs). This feature simplifies writing and managing complex queries. Go to [`WITH` templates playground](https://victoriametrics.com/promql/expand-with-exprs) and try it.
 - Metric names and metric labels may contain escaped chars. For instance, `foo\-bar{baz\=aa="b"}` is valid expression. It returns time series with name `foo-bar` containing label `baz=aa` with value `b`. Additionally, `\xXX` escape sequence is supported, where `XX` is hexadecimal representation of escaped char.
diff --git a/docs/Home.md b/docs/Home.md
index 116b338d87..1cd7b74b5b 100644
--- a/docs/Home.md
+++ b/docs/Home.md
@@ -3,10 +3,11 @@
 * [Quick start](Quick-Start)
 * [`WITH` templates playground](https://play.victoriametrics.com/promql/expand-with-exprs)
 * [Grafana playground](http://play-grafana.victoriametrics.com:3000/d/4ome8yJmz/node-exporter-on-victoriametrics-demo)
-* [PromQL extensions](ExtendedPromQL)
+* [MetricsQL](ExtendedPromQL)
 * [Single-node version](Single-server-VictoriaMetrics)
 * [FAQ](FAQ)
 * [Cluster version](Cluster-VictoriaMetrics)
 * [Articles](Articles)
+* [CaseStudies](Case studies)
 * [vmbackup](vmbackup)
 * [vmrestore](vmrestore)
diff --git a/docs/Single-server-VictoriaMetrics.md b/docs/Single-server-VictoriaMetrics.md
index 241af1b334..b311e19511 100644
--- a/docs/Single-server-VictoriaMetrics.md
+++ b/docs/Single-server-VictoriaMetrics.md
@@ -18,7 +18,7 @@ Cluster version is available [here](https://github.com/VictoriaMetrics/VictoriaM
 ## Prominent features
 
 * Supports [Prometheus querying API](https://prometheus.io/docs/prometheus/latest/querying/api/), so it can be used as Prometheus drop-in replacement in Grafana.
-  Additionally, VictoriaMetrics extends PromQL with opt-in [useful features](https://github.com/VictoriaMetrics/VictoriaMetrics/wiki/ExtendedPromQL).
+  VictoriaMetrics implements [MetricsQL](https://github.com/VictoriaMetrics/VictoriaMetrics/wiki/ExtendedPromQL) query language, which is inspired by PromQL.
 * Supports global query view. Multiple Prometheus instances may write data into VictoriaMetrics. Later this data may be used in a single query.
 * High performance and good scalability for both [inserts](https://medium.com/@valyala/high-cardinality-tsdb-benchmarks-victoriametrics-vs-timescaledb-vs-influxdb-13e6ee64dd6b)
   and [selects](https://medium.com/@valyala/when-size-matters-benchmarking-victoriametrics-vs-timescale-and-influxdb-6035811952d4).
@@ -395,6 +395,18 @@ VictoriaMetrics supports the following handlers from [Prometheus querying API](h
 
 These handlers can be queried from Prometheus-compatible clients such as Grafana or curl.
 
+VictoriaMetrics accepts additional args for `/api/v1/labels` and `/api/v1/label/.../values` handlers.
+See [this feature request](https://github.com/prometheus/prometheus/issues/6178) for details:
+
+* Any number [time series selectors](https://prometheus.io/docs/prometheus/latest/querying/basics/#time-series-selectors) via `match[]` query arg.
+* Optional `start` and `end` query args for limiting the time range for the selected labels or label values.
+
+Additionally VictoriaMetrics provides the following handlers:
+
+* `/api/v1/series/count` - it returns the total number of time series in the database. Note that this handler scans all the inverted index,
+  so it can be slow if the database contains tens of millions of time series.
+* `/api/v1/labels/count` - it returns a list of `label: values_count` entries. It can be used for determining labels with the maximum number of values.
+
 
 ### How to build from sources