metrics: accept any viable target update

Author: pared

content/docs/command-reference/metrics/diff.md

@@ -41,10 +41,11 @@ lists all the current metrics without comparisons.
 
 ## Options
 
-- `--targets <paths>` - limit command scope to these metric files. Using -R,
-  directories to search metric files in can also be given. When specifying
-  arguments for `--targets` before `revisions`, you should use `--` after this
-  option's arguments, e.g.:
+- `--targets <paths>` - limit command scope to these metrics files (supports any
+  file, even when not found as `metrics` in `dvc.yaml`). Using `-R`, directories
+  to search metric files in can also be given. When specifying arguments for
+  `--targets` before `revisions`, you should use `--` after this option's
+  arguments, e.g.:
 
   ```dvc
   $ dvc metrics diff --targets t1.json t2.yaml -- HEAD v1

content/docs/command-reference/metrics/show.md

@@ -22,11 +22,11 @@ Finds and prints all metrics in the <abbr>project</abbr> by examining all of its
 > This kind of metrics can be defined with the `-m` (`--metrics`) and `-M`
 > (`--metrics-no-cache`) options of `dvc run`.
 
-If `targets` are provided, it will show those specific metric files instead.
-With the `-a` or `-T` options, this command shows the different metrics values
-across all Git branches or tags, respectively. With the `-R` option, some of the
-target can even be directories, so that DVC recursively shows all metric files
-inside.
+If `targets` are provided, it will show those specific files instead, even if
+they are not marked as `metric` type in `dvc.yaml`. With the `-a` or `-T`
+options, this command shows the different metrics values across all Git branches
+or tags, respectively. With the `-R` option, some of the target can even be
+directories, so that DVC recursively shows all metric files inside.
 
 An alternative way to display metrics is the `dvc metrics diff` command, which
 compares them with a previous version.

content/docs/command-reference/plots/diff.md

@@ -45,9 +45,8 @@ please see `dvc plots`.
 
 ## Options
 
-- `--targets <path>` - specific metric files to visualize. These must be listed
-  in a [`dvc.yaml`](/doc/user-guide/dvc-files-and-directories#dvcyaml-file) file
-  (see the `--plots` option of `dvc run`). When specifying arguments for
+- `--targets <path>` - specific metric files to visualize (supports any file,
+  even when not found as `plots` in `dvc.yaml`). When specifying arguments for
   `--targets` before `revisions`, you should use `--` after this option's
   arguments, e.g.:
 

content/docs/command-reference/plots/show.md

@@ -22,8 +22,8 @@ This command provides a quick way to visualize metrics such as loss functions,
 AUC curves, confusion matrices, etc. All plots defined in `dvc.yaml` are used by
 default.
 
-Optionally, specific metric file `targets` to show are accepted. These must be
-listed in a `dvc.yaml` file (see the `--plots` option of `dvc run`).
+Optionally, specific metric file `targets` to show are accepted. They do not not
+have to be specified as `plots` in `dvc.yaml`.
 
 The plot style can be customized with
 [plot templates](/doc/command-reference/plots#plot-templates), using the