-Indicate that one or more input parameters are "secret". Must be applied at the top level Workflow. Secret parameters are not stored in keep, are hidden from logs and API responses, and are wiped from the database after the workflow completes.
+This is an optional extension field appearing on the standard @DockerRequirement@. It specifies the portable data hash of the Arvados collection containing the Docker image. If present, it takes precedence over @dockerPull@ or @dockerImageId@.
+
+<pre>
+requirements:
+ DockerRequirement:
+ dockerPull: "debian:9"
+ arv:dockerCollectionPDH: "feaf1fc916103d7cdab6489e1f8c3a2b+174"
+</pre>
+
+h1. Deprecated extensions
+
+The following extensions are deprecated because equivalent features are part of the CWL v1.1 standard.
+
+h2. cwltool:LoadListingRequirement
+
+For CWL v1.1 scripts, this is deprecated in favor of "loadListing":https://www.commonwl.org/v1.1/CommandLineTool.html#CommandInputParameter or "LoadListingRequirement":https://www.commonwl.org/v1.1/CommandLineTool.html#LoadListingRequirement
+
+In CWL v1.0 documents, the default behavior for Directory objects is to recursively expand the @listing@ for access by parameter references an expressions. For directory trees containing many files, this can be expensive in both time and memory usage. Use @cwltool:LoadListingRequirement@ to change the behavior for expansion of directory listings in the workflow runner.