Update readme to specify BSD / OSX limits.
diff --git a/README.md b/README.md
index a4a4fac..bf686aa 100644
--- a/README.md
+++ b/README.md
@@ -66,5 +66,8 @@
* No, you must add watches for any directory you want to watch.
* Do I have to watch the Error and Event channels in a separate goroutine?
* As of now, yes. Looking into making this single-thread friendly.
-* How avoid the criptic error "no space left on device" when adding watches?
- * Probably you're out of inotify's watches; verify your max with "cat /proc/sys/fs/inotify/max\_user\_watches".
+* There are OS-specific limits as to how many watches can be created:
+ * Linux: /proc/sys/fs/inotify/max_user_watches contains the limit,
+ reaching this limit results in a "no space left on device" error.
+ * BSD / OSX: sysctl variables "kern.maxfiles" and "kern.maxfilesperproc",
+ reaching these limits results in a "too many open files" error.
