Field `additional_urls` to download additional videos from metadata

1 files changed, 3 insertions, 1 deletions

diff --git a/README.md b/README.md
index e1022da37..d3856dc9f 100644
--- a/README.md
+++ b/README.md
@@ -1279,7 +1279,9 @@ The metadata obtained the the extractors can be modified by using `--parse-metad
 
 Note that any field created by this can be used in the [output template](#output-template) and will also affect the media file's metadata added when using `--add-metadata`.
 
-You can also use this to change only the metadata that is embedded in the media file. To do this, set the value of the corresponding field with a `meta_` prefix. For example, any value you set to `meta_description` field will be added to the `description` field in the file. You can use this to set a different "description" and "synopsis", for example.
+This option also has a few special uses:
+1. You can use this to change the metadata that is embedded in the media file. To do this, set the value of the corresponding field with a `meta_` prefix. For example, any value you set to `meta_description` field will be added to the `description` field in the file. You can use this to set a different "description" and "synopsis", for example
+2. You can download an additional URL based on the metadata of the currently downloaded video. To do this, set the field `additional_urls` to the URL that you want to download. Eg: `--parse-metadata "description:(?P<additional_urls>https?://www\.vimeo\.com/\d+)` will download the first vimeo video found in the description
 
 ## Modifying metadata examples