+To control if an individual step can be reused, use "WorkReuse":https://www.commonwl.org/v1.1/CommandLineTool.html#WorkReuse instead of the deprecated @arv:ReuseRequirement@.
+
+h2(#performance). Performance
+
+When combining a parameter value with a string, such as adding a filename extension, write @$(inputs.file.basename).ext@ instead of @$(inputs.file.basename + 'ext')@. The first form is evaluated as a simple text substitution, the second form (using the @+@ operator) is evaluated as an arbitrary Javascript expression and requires that you declare @InlineJavascriptRequirement@.
+
+Use @ExpressionTool@ to efficiently rearrange input files between steps of a Workflow. For example, the following expression accepts a directory containing files paired by @_R1_@ and @_R2_@ and produces an array of Directories containing each pair.
+
+{% codeblock as yaml %}