diff --git a/README.md b/README.md
index 99e5ab30..82ad247a 100644
--- a/README.md
+++ b/README.md
@@ -1793,7 +1793,8 @@ Notes:
         - `new_type`: [string='current'] [git,file,output,multivar,current] How to interpret the `new` name. Use `git` for a git hash, branch, etc.
                       Use `current` for the currently loaded PCB/Schematic.
                       Use `file` for a file name. Use `output` to specify the name of a `pcb_variant`/`sch_variant` output.
-                      Use `multivar` to compare a set of variants, in this mode `new` is the list of variants.
+                      Use `multivar` to compare a set of variants, in this mode `new` is the list of outputs for the variants.
+                      This is an extension of the `output` mode.
                       If `old` is also `multivar` then it becomes the reference, otherwise we compare using pairs of variants.
         - `old`: [string='HEAD'] Reference file. When using git use `HEAD` to refer to the last commit.
                  Use `HEAD~` to refer the previous to the last commit.
diff --git a/docs/samples/generic_plot.kibot.yaml b/docs/samples/generic_plot.kibot.yaml
index f4d9b833..8c4419d1 100644
--- a/docs/samples/generic_plot.kibot.yaml
+++ b/docs/samples/generic_plot.kibot.yaml
@@ -540,7 +540,8 @@ outputs:
       # [string='current'] [git,file,output,multivar,current] How to interpret the `new` name. Use `git` for a git hash, branch, etc.
       # Use `current` for the currently loaded PCB/Schematic.
       # Use `file` for a file name. Use `output` to specify the name of a `pcb_variant`/`sch_variant` output.
-      # Use `multivar` to compare a set of variants, in this mode `new` is the list of variants.
+      # Use `multivar` to compare a set of variants, in this mode `new` is the list of outputs for the variants.
+      # This is an extension of the `output` mode.
       # If `old` is also `multivar` then it becomes the reference, otherwise we compare using pairs of variants
       new_type: 'current'
       # [string='HEAD'] Reference file. When using git use `HEAD` to refer to the last commit.
diff --git a/kibot/out_diff.py b/kibot/out_diff.py
index fb3c3b37..a3b9c2d9 100644
--- a/kibot/out_diff.py
+++ b/kibot/out_diff.py
@@ -69,7 +69,8 @@ class DiffOptions(BaseOptions):
             """ [git,file,output,multivar,current] How to interpret the `new` name. Use `git` for a git hash, branch, etc.
                 Use `current` for the currently loaded PCB/Schematic.
                 Use `file` for a file name. Use `output` to specify the name of a `pcb_variant`/`sch_variant` output.
-                Use `multivar` to compare a set of variants, in this mode `new` is the list of variants.
+                Use `multivar` to compare a set of variants, in this mode `new` is the list of outputs for the variants.
+                This is an extension of the `output` mode.
                 If `old` is also `multivar` then it becomes the reference, otherwise we compare using pairs of variants """
             self.cache_dir = ''
             """ Directory to cache the intermediate files. Leave it blank to disable the cache """