-The target dynamic scope must be specified explicitly when referring to
-a field outside of the local static scope (a local static scope contains
-all fields present within the same scope, at the same nesting level).
+Multiple declarations of the same field name within a local static scope
+is not valid. It is however valid to re-use the same field name in
+different local scopes.
+
+Nested static and dynamic scopes form lookup paths. These are used for
+variant tag and sequence length references. They are used at the variant
+and sequence definition site to look up the location of the tag field
+associated with a variant, and to lookup up the location of the length
+field associated with a sequence.
+
+Variants and sequences can refer to a tag field either using a relative
+path or an absolute path. The relative path is relative to the scope in
+which the variant or sequence performing the lookup is located.
+Relative paths are only allowed to lookup within the same static scope,
+which includes its nested static scopes. Lookups targeting parent static
+scopes need to be performed with an absolute path.
+
+Absolute path lookups use the full path including the dynamic scope
+followed by a "." and then the static scope. Therefore, variants (or
+sequences) in lower levels in the dynamic scope (e.g. event context) can
+refer to a tag (or length) field located in upper levels (e.g. in the
+event header) by specifying, in this case, the associated tag with
+<stream.event.header.field_name>. This allows, for instance, the event
+context to define a variant referring to the "id" field of the event
+header as selector.
+