X-Series
########


DIRECTORY
=========

Information technology - Open Systems Interconnection::

    X.500
      The Directory: Overview of concepts, models and services  
    X.Imp500
      Directory Implementors' Guide  
    X.501
      The Directory: Models  
    X.509
      The Directory: Public-key and attribute certificate frameworks  
    X.510
      The Directory: Protocol specifications for secure operations  
    X.511
      The Directory: Abstract service definition  
    X.518
      The Directory: Procedures for distributed operation  
    X.519
      The Directory: Protocol specifications  
    X.520
      The Directory: Selected attribute types  
    X.521
      The Directory: Selected object classes  
    X.525
      The Directory: Replication  
    X.530
      The Directory: Use of systems management for administration of the Directory  


* X.500 定义了一种区别命名规则，以命名树来确保用户名称的唯一性
* X.509 则为 X.500 用户名称提供了通信实体鉴别机制，并规定了实体鉴别过程中广泛适用的证书语法和数据接口





ASN.1
=====

Information technology - Abstract Syntax Notation One (ASN.1)::

    X.680
       Specification of basic notation  
    X.681
       Information object specification  
    X.682
       Constraint specification  
    X.683
       Parameterization of ASN.1 specifications  

Information technology - ASN.1 encoding rules::

    X.690
      Specification of Basic Encoding Rules (BER)
      Canonical Encoding Rules (CER)
      Distinguished Encoding Rules (DER)  
    X.691
      Specification of Packed Encoding Rules (PER)  
    X.692
      Specification of Encoding Control Notation (ECN)  
    X.693
      XML Encoding Rules (XER)  
    X.694
      Mapping W3C XML schema definitions into ASN.1  
    X.695
      Registration and application of PER encoding instructions  
    X.696
      Specification of Octet Encoding Rules (OER)  
    X.697
      Specification of JavaScript Object Notation Encoding Rules (JER)  






参考
====

* X Series: https://www.itu.int/rec/T-REC-X/en