Path: utzoo!attcan!uunet!decwrl!ucbvax!CS.UCL.AC.UK!S.Walton
From: S.Walton@CS.UCL.AC.UK (Simon Walton)
Newsgroups: comp.protocols.iso
Subject: Re: Escape sequences in ASN.1 character strings
Message-ID: <19316.648733166@UK.AC.UCL.CS>
Date: 23 Jul 90 11:39:26 GMT
References: <997@sl10c.concurrent.co.uk>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 19


> Are values in ASN.1 character string types that by default include no Cn
> sets (e.g. Graphic String) permitted to load a Cn set via an escape
> sequence?  I should appreciate a reference to appropriate defining
> text.

   When using basic encoding rules the representation for
GraphicString may contain escape sequences to invoke Cn
character sets. NumericString, PrintableString and
VisibleString (ISO646String) may not contain escape sequences
(or control characters). In ASN.1 the character strings
themselves contain no escape sequences, just the actual
characters. Use of escape sequences is a matter for the
transfer syntax (ie. BER). ISO 2022 defines the use of escape
sequences, ISO 2375 together with the International Register of
Coded Character Sets defines the characters and their
registration numbers. The Register is administrated by ECMA.

Simon