anchor.diff:          acceptschema2: false <1>
           enforcequota: false <2>
           projectcachettl: 1m <3>
  -----
  -<1> A configuration option that can be overridden by the boolean environment variable `*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ACCEPTSCHEMA2*`, which allows for the ability to accept manifest schema v2 on manifest put requests.
  -<2> A configuration option that can be overridden by the boolean environment variable `*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ENFORCEQUOTA*`, which allows the ability to turn quota enforcement on or off. By default, quota enforcement is off. It overrides {product-title} middleware configuration option. Recognized values are *true* and *false*.
  -<3> A configuration option that can be overridden by the environment variable `*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_PROJECTCACHETTL*`, specifying an eviction timeout for project quota objects. It takes a valid time duration string (for example, *2m*). If empty, you get the default timeout. If zero (*0m*), caching is disabled.
  +        blobrepositorycachettl: 10m <4>
  +----
  +<1> A configuration option that can be overridden by the boolean environment
  +variable `*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ACCEPTSCHEMA2*`, which
  +allows for the ability to accept manifest schema v2 on manifest put requests.
  +<2> A configuration option that can be overridden by the boolean environment
  +variable `*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ENFORCEQUOTA*`, which
  +allows the ability to turn quota enforcement on or off. By default, quota
  +enforcement is off. It overrides {product-title} middleware configuration
  +option. Recognized values are *true* and *false*.
  +<3> A configuration option that can be overridden by the environment variable
  +`*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_PROJECTCACHETTL*`, specifying an
  +eviction timeout for project quota objects. It takes a valid time duration
  +string (for example, *2m*). If empty, you get the default timeout. If zero
  +(*0m*), caching is disabled.
  +<4> A configuration option that can be overriden by the environment variable
  +`*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_BLOBREPOSITORYCACHETTL*`, specifying
  +an eviction timeout for associations between blob and containing repository.
  +The format of the value is the same as in `projectcachettl` case.
   ====
   
   [[middleware-repository-pullthrough]]
  
positive.code:         pullthrough: true
          enforcequota: false
          projectcachettl: 1m
    storage:
      - name: openshift
  ----
  
negative.code:         pullthrough: true <3>
          enforcequota: false <4>
          projectcachettl: 1m <5>
          blobrepositorycachettl: 10m <6>
    storage:
      - name: openshift <1>
  ----
  