BOX Grammar

[1] BOX ::= Encoding Node*

[2] Encoding ::= 'A' | 'U'

'A' for ASCII, 'U' for UTF-8

[3] Node ::= (TypeCode TextSpec) | (TypeCodePlus Index)

1st option if first time the text is encountered; 2nd option otherwise

[4] TypeCode ::= 0 | 10 | ... | 90

See this for meaning of the values.

[5] TypeCodePlus ::= TypeCode plus IndexLength

[6] IndexLength ::= 1 | 2 | 4

[7] TextSpec ::= Length Text

[8] Length ::= a two byte integer

[9] Text ::= ASCII or UTF-8 text

[10] Index ::= a one, two or four-byte integer