Help! Syntax &normalize

[Guolion <glr2000@263.net>]

Hi all,
sorry for my english.
I'm reading   source code of OpenLDAP2.0.6. I am a new user and C coder.
I can't find Syntax 's normalize method have any reality. 
So these statements I can't understand.
in register_ayntax():
> code = syn_add( syn, flags, validate, ber2str, str2ber, &err);

but 

int   syn_add(
    LDAPSyntax		*syn,
    unsigned flags,
    slap_syntax_validate_func	*validate,
    slap_syntax_transform_func	*normalize,
    slap_syntax_transform_func	*pretty,
#ifdef SLAPD_BINARY_CONVERSION
    slap_syntax_transform_func	*ber2str,
    slap_syntax_transform_func	*str2ber,
#endif
    const char		**err
)

what does it mean?Where is normalize and pretty?
-- 
The End.