It's all in the details, from man-pages(7):
Formatting conventions for manual pages describing functions
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Variable names should, like argument names, be specified in italics.
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Formatting conventions (general)
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Special macros, which are usually in uppercase, are in bold.
Exception: don't boldface NULL.
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Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/10034)
We add new functions for getting parameters and discovering the gettable
and settable parameters. We also make EVP_PKEY_CTX_get_signature_md() a
function and implement it in terms of the new functions.
This enables applications to discover the set of parameters that are
supported for a given algorithm implementation.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9753)