Status of Annex G??

William Pimentel w-piment at UNIANDES.EDU.CO
Mon Mar 22 12:37:27 EST 1999

Hi Henri,

the "three dots" that you are referring to are specified in X.681 Amendment
1: "Rules of extensibility". The dots are called an "extension marker" and
they are used (in the case of the H.323 series) to demarcate the parts of
the ASN.1 elements that were added for a particular version of the
specification. So below a marker you will find newer additions to the


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> -----Original Message-----
> From: henri.maenpaa at NOKIA.COM [mailto:henri.maenpaa at NOKIA.COM]
> Sent: 22 March 1999 10:49
> Subject:      basic ASN.1 coding question
> Hi everyone,
> I have a pretty basic/specific question about ASN.1 coding:
> what's the semantic difference if a particular information element is
> located above/below the "three dots"-line in an ASN.1 structure?
> -Henri Mäenpää

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