> Is IMPLICIT only mean that: When several Tags express a same parameter, > then only use one tag to express the parameter?
No, that's not quite right. An IMPLICIT tag replaces the tag that would have followed it; it does not guarantee that only one tag is used. I think the example below will make this clear. If I have I ::= [5][6][7] INTEGER i I ::= 9 the BER encoding of i would be A5 07 A6 05 A7 03 02 01 09, that is, there are 4 tags (including the [UNIVERSAL 2] tag for INTEGER). I ::= [5][6][7] IMPLICIT INTEGER would have an encoding of A5 05 A6 03 87 01 09, that is, the [7] IMPLICIT replaces the [UNIVERSAL 2]. Note that the word IMPLICIT only applies to the [7], not to the whole set of tags. Likewise I ::= [5] IMPLICIT [6] IMPLICIT [7] IMPLICIT INTEGER would have an encoding of 85 01 09, whereby - the [7] IMPLICIT has replaced the [UNIVERSAL 2], - the [6] IMPLICIT has replaced the [7] IMPLICIT, and - the [5] IMPLICIT has replaced the [6] IMPLICIT. Clearly all these examples are not practical and serve only for illustration. ===================================================================== Conrad Sigona Toll Free : 1-888-OSS-ASN1 OSS Nokalva Voice Mail : 1-732-302-9669 x400 [EMAIL PROTECTED] Fax : 1-419-831-5035 http://www.oss.com My direct line : 1-315-845-1773
