Update source/reference-manual/ota/advanced-tagging.rst

Co-authored-by: vkhoroz <vkhoroz@users.noreply.github.com>

source/reference-manual/ota/advanced-tagging.rst

@@ -19,7 +19,9 @@ This is the base OS image.
 It represents an immutable combination of the Platform build's OSTree hash with the output of a container build.
 
 **Tag**: A Target has a "custom" section where with a list of Tags.
-The tags can be used to say things like this is a "development" build or this is a "production" build.
+**Tag:**: A user defined attribute of a Target designating its intended usage.
+Tags are defined in the "custom" section of a Target.
+They can be used to e.g. distinguish between "development" versus "production" builds.
 
 Scenario 1: A new Platform Build That Re-Uses Containers
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