--- a/doc/gutentags.txt	Tue Aug 09 22:12:46 2016 -0700
+++ b/doc/gutentags.txt	Thu Sep 22 20:58:46 2016 -0700
@@ -59,8 +59,27 @@
 always consistent with the source code.
 
 Also, Gutentags is clever enough to not stumble upon itself by triggering
-multiple ctags processes if you save files too fast, or your project is really
-big.
+multiple ctags processes if you save files too fast, or if your project is
+really big.
+
+
+1.1 Requirements
+
+If you're using the `ctags` modules (which is the default and only working one
+at this point, really), you will need a `tags` generator that supports the
+following arguments:
+
+* `-f` (to specify the output file)
+* `--append` (to append to an existing file while keeping it sorted)
+* `--exclude` (to exclude file patterns)
+* `--options` (to specify an options file)
+
+This means you probably want Exhuberant Ctags or Universal Ctags. The basic
+old BSD Ctags WON'T WORK. Other language-specific versions may or may not
+work. Check with their help or man page.
+
+
+1.2 Similar Plugins
 
 There are some similar Vim plugins out there ("vim-tags", "vim-autotag",
 "vim-automatic-ctags", etc.). They all fail on one or more of the requirements