[gnome-software.wiki] Update Software metadata

[Philip Withnall <pwithnall src gnome org>]

commit 38a6c4ce05aa6032d6cad3be50fdc677655ef114
Author: Philip Withnall <philip tecnocode co uk>
Date:   Fri Sep 17 13:23:08 2021 +0000

    Update Software metadata

 Software-metadata.md | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)
---
diff --git a/Software-metadata.md b/Software-metadata.md
index ff13067..64e71fb 100644
--- a/Software-metadata.md
+++ b/Software-metadata.md
@@ -144,15 +144,22 @@ For example:
 How to add missing hardware information
 ---
 
-- TODO
-- See [this blog 
post](https://tecnocode.co.uk/2021/07/12/add-metadata-to-your-app-to-say-what-inputs-and-display-sizes-it-supports/).
-- Unfortunately this data, if present, is currently [stripped by 
Flathub](https://github.com/flathub/flathub/issues/2439).
+The hardware information for an application is stored in the [`<requires>` and 
`<recommends>`](https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#tag-requires-recommends)
 elements within the application’s `<component>` in its metainfo file.
+
+GNOME Software currently understands the 
[`<control>`](https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#tag-requires-recommends-control)
 and 
[`<display_length>`](https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#tag-requires-recommends-display_length)
 elements.
+
+See [this blog 
post](https://tecnocode.co.uk/2021/07/12/add-metadata-to-your-app-to-say-what-inputs-and-display-sizes-it-supports/)
 or [this blog post](https://blogs.gnome.org/tbernard/2021/09/07/ready-for-software-41/#device-support) for 
examples of metadata.
+
+Unfortunately this data, if present, is currently [stripped by 
Flathub](https://github.com/flathub/flathub/issues/2439), which means that if it’s added in applications’ 
metainfo files, it currently won’t appear in the appstream file published by flathub. This issue is being 
worked on.
 
 How to add missing content rating information
 ---
 
- - https://hughsie.github.io/oars/
- - TODO
+The content rating information for an application is stored in the 
[`<content_rating>`](https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#tag-content_rating)
 element within the application’s `<component>` in its metainfo file.
+
+Applications should use the OARS 1.1 standard to fill in this element. If the `<content_rating>` element is 
not specified, the application’s content rating is unknown. If it’s specified but empty, the application has 
no content which might be unsuitable for any audience.
+
+Use [the OARS generator](https://hughsie.github.io/oars/) to produce suitable content rating information for 
an application.
 
 How to fix incorrect licensing information
 ---