No subject

A The QUOTED-PRINTABLE inline encoding has been eliminated.
  Only the "B" encoding of [RFC 2047] is an allowed value for
  the ENCODING parameter.

LABEL;ENCODING=QUOTED-PRINTABLE:123 Winding Way=0D=0A=
  Any Town, CA 12345=0D=0A=
  USA

B The method for specifying CRLF character sequences in text
  type values has been changed. The CRLF character sequence in
  a text type value is specified with the backslash character
  sequence "\n" or "\N".

With 2.1 if the value contains a CRLF then the value must be
Quoted-Printable or Base64 encoded.

C Any COMMA or SEMICOLON in a text type value must be backslash
  escaped.

I do not understand why this is listed as a difference,  the v2.1
document I have says the same thing.

<quote>To include a semicolon in this string, it must be escaped with a
"\" character.</quote>

D The [MIME-DIR] predefined types of SOURCE, NAME and PROFILE
  are allowed.

It seems to me that if these values come through on a v2.1 vCard it
really doesn't have a negative effect.

E The [MIME-DIR] VALUE type parameter for value data typing is
  allowed. In addition, there are extensions made to these type
  values for additional value types used in this specification.

F The [VCARD] CHARSET type parameter has been eliminated.
  Character set can only be specified on the CHARSET parameter
  on the Content-Type MIME header field.

G The [VCARD] support for non-significant WSP character has
  been eliminated.

H The "TYPE=" prefix to parameter values is required. In
  [VCARD] this was optional.

    * 2.1: TEL;WORK;VOICE:(111) 555-1212
    * 3.0: TEL;TYPE=WORK,VOICE:(111) 555-1212

  This is a difference that currently really hurts me.

I LOGO, PHOTO and SOUND multimedia formats MUST be either IANA
  registered types or non-standard types.

J Inline binary content must be "B" encoded and folded. A blank
  line after the encoded binary content is no longer required.

K TEL values can be identified as personal communication
  services telephone numbers with the PCS type parameter value.

L The CATEGORIES, CLASS, NICKNAME, PRODID and SORT-STRING types
  have been added.

M The VERSION, N and FN types MUST be specified in a vCard.
  This identifies the version of the specification that the
  object was formatted to. It also assures that every vCard
  will include both a structured and formatted name that can be
  used to identify the object.