The <Comment> Block
Documentation/UserGuide/Comment Block
Provides self-documentation of the input file. The variables in this block are not used in the code. This block is optional. Example:
<comment>
problem = Brio & Wu shock tube
author = M. Brio & C. C. Wu
journal = J. Comp. Phys. 75, 400-422 (1988)
config = --with-problem=shkset1d