submodule tailf-meta-extensions {

    yang-version 1;

    belongs-to tailf-common {
        prefix tailf;
    }

    organization "Tail-f Systems";

    description
      "This submodule defines Tail-f YANG meta extensions statements.

     Copyright 2019 Cisco Systems, Inc.
     All rights reserved.
     Permission is hereby granted to redistribute this file without
     modification.";

    revision "2017-03-08" {
      description
        "Released as part of ConfD-6.4 / NCS-4.4.

       Corrected the pattern for the tailf:tailf-oid typedef.";
    }

    revision "2016-11-24" {
      description
        "Released as part of ConfD-6.3.

       Added tailf:identifier-ref.";
    }

    revision "2013-11-07" {
      description
        "Released as part of ConfD-5.0.

       Added tailf:occurrence.";
    }

    revision "2010-08-19" {
      description
        "Released as part of ConfD-3.3.1.

       Added tailf:snmp-identifier.";
    }

    revision "2010-03-18" {
      description
        "Released as part of ConfD-3.2.";
    }


    typedef identifier {
      type string {
        pattern "[A-Za-z_][A-Za-z0-9_-]*";
      }
    }

    typedef identifier-ref {
      type string {
        pattern
          "([A-Za-z_][A-Za-z0-9_-]*:)?[A-Za-z_][A-Za-z0-9_-]*";
      }
    }

    typedef snmp-identifier {
      type string {
        pattern
          "[A-Za-z_][A-Za-z0-9_-]*(:[A-Za-z_][A-Za-z0-9_-]*)*";
      }
    }

    typedef tailf-oid {
      type string {
        pattern
          '(([0-1](\.[1-3]?[0-9]))'
            + '|(2.(0|([1-9]\d*)))'
            + '|([A-Za-z_][A-Za-z0-9_-]*))?'
            + '(\.(0|([1-9]\d*)))+';
      }
    }

    extension use-in {
      tailf:arg-type {
        type "string";
      }
      tailf:use-in "extension";
      tailf:occurence "*";
      argument "name" {
        yin-element false;
      }
      description
        "Specifies in which statements a particular extension statement can be
      used.";
    }

    extension substatement {
      tailf:arg-type {
        type "string";
      }
      tailf:use-in "extension";
      tailf:occurence "*";
      tailf:substatement "tailf:occurence";
      argument "name" {
        yin-element false;
      }
      description
        "Specifies which statements can occur as substatement to the
      given statement.";
    }

    extension arg-type {
      tailf:use-in "argument";
      tailf:substatement "type" {
        tailf:occurence "1";
      }
      tailf:substatement "default";
      description
        "Specifies the type of the argument.";
    }

    extension occurence {
      tailf:arg-type {
        type "enumeration" {
          enum "?" {
            description "The extension may be given zero or one time.
This is the default.";
          }
          enum "*" {
            description "The extension may be given zero or multiple times.";
          }
          enum "+" {
            description "The extension must be given at least once.";
          }
          enum "1" {
            description "The extension must be given exactly once.";
          }
        }
      }
      tailf:use-in "extension";
      argument "value" {
        yin-element false;
      }
      description
        "Specifies how an extension statement may be used.

       If this statement is given as a substatement to 'extension',
       it applies to all 'use-in' statements.

       If this statement is given as a substatement to 'tailf:substatement',
       it applies to this substatement.";
    }
  }  // submodule tailf-meta-extensions