S99: spotted "synthetic character" on #p6. Added entries"

S99-glossary.pod

@@ -1538,6 +1538,8 @@ No Such Thing.
 The name of the main branch of current L</Rakudo> in L</git>.  Originally
 named so for its "new object model".
 
+=head2 Normalization Form
+
 =head2 NPE
 
 Null Pointer Exception.
@@ -1854,6 +1856,14 @@ An operator that comes before the term it belongs to, for example
 L<expression|/Expression> used in a L</boolean context> by a
 L</control flow> L</statement>.
 
+=head2 precomposed character
+
+A composite character (that is, formed of many L</codepoint>s), for
+which L</Unicode> assigns a codepoint. Thanks to L</NFG>, a composite
+non precomposed character (aka a L</synthetic character|synthetic
+one>) has its own dynamically assigned codepoint.
+
+
 =head2 private
 
 =head2 process
@@ -2391,6 +2401,14 @@ See L</parser>.
 
 See L</Huffmanization>.
 
+=head2 synthetic character
+
+A L</grapheme> composed of many L</codepoint>s that is not a
+</precomposed character>.  L</NFG> dynamically assigns its own
+codepoint for such a composition. A composite grapheme to which
+Unicode assigns a codepoint is a L<precomposed character>.
+
+
 =head1 T
 
 =head2 tail call