(defvar nnheader-max-head-length 4096
"*Max length of the head of articles.
-Value is an integer, nil, or t. Nil means read in chunks of a file
+Value is an integer, nil, or t. nil means read in chunks of a file
indefinitely until a complete head is found\; t means always read the
entire file immediately, disregarding `nnheader-head-chop-length'.