Clarify robots protocol support

Closes #351, #353

README.md

@@ -10,9 +10,11 @@ Heritrix is the Internet Archive's open-source, extensible, web-scale, archival-
 
 ## Crawl Operators!
 
-Heritrix is designed to respect the [`robots.txt`](http://www.robotstxt.org/robotstxt.html) exclusion directives and [META robots tags](http://www.robotstxt.org/meta.html). Please consider the
+Heritrix is designed to respect the [`robots.txt`](http://www.robotstxt.org/robotstxt.html) exclusion directives<sup>†</sup> and [META nofollow tags](http://www.robotstxt.org/meta.html). Please consider the
 load your crawl will place on seed sites and set politeness policies accordingly. Also, always identify your crawl with contact information in the `User-Agent` so sites that may be adversely affected by your crawl can contact you or adapt their server behavior accordingly.
 
+<sup>†</sup> The newer wildcard extension to robots.txt is [not yet](https://github.com/internetarchive/heritrix3/issues/250) supported.
+
 ## Getting Started
 
 - [User Manual](https://github.com/internetarchive/heritrix3/wiki)