diff --git a/README.md b/README.md
index ac01e6c109c381e414d2ea2b7b1f183fda4c0dcd..7f63144aa575c4af9bdb5417e03c6ccde9fcc965 100644
--- a/README.md
+++ b/README.md
@@ -5,19 +5,22 @@ A script to de-googlify CSS files, downloading relevant fonts in the process. Be
 ## Usage
 
 ```
-./degooglify.sh [ https://fonts.googleapis.com/css?(...) | file.css ]
+./degooglify.sh [ 'https://fonts.googleapis.com/css?(...)' | file.css ]
 ```
 
+**Please note: remember to put the URL in quotes, or otherwise escape any special characters.**  
+Google Fonts CSS URLs contain the pipe character (`|`) which will be interpreted by your shell and cause the URL passed to `degooglify.sh` to be incomplete.
+
 ## Operation
 
 The `degooglify.sh` script takes as arguments local files and URLs (leading to `fonts.googleapis.com`). It handles multiple arguments, including mixing of URLs and files.
 
 It then downloads the CSS files from URLs provided, and in all local and downloaded files looks for `@import` (with URL pointing to `fonts.googleapis.com`) and `src:` (with URL pointing to `fonts.gstatic.com`) statements.
 
-For relevant `@import` statements it then:
-1. downloads the CSS files, saving them locally
-1. replaces the URL with the local file name generated based on the URL
-1. degooglifies the downloaded file
+For relevant `@import` statements it will:
+1. download the CSS files, saving them locally
+1. replace the URL with the local file name generated based on the URL
+1. degooglify the downloaded file
 
 For relevant `src:` statements it:
 1. downloads the font files into the `fonts/` subdirectory
@@ -38,6 +41,16 @@ This is designed to give an informative file name, containing font families, sty
 
 For font URLs, the file names of downloaded files are generated by taking the font name from `local()` stanza in the `src:` statement, and adding the extension taken from the URL.
 
+## Dependencies
+
+An attempt is made to keep dependencies down to as few as possible. Currently these are:
+ - Bash 3.x+
+ - either `curl` or `wget`
+ - GNU `sed` (or any other `sed` flavor that supports: `-i`, `-e`, `-E`)
+ - GNU `grep` (or any other `grep` flavor that supports extended regexen)
+ - `tr`
+ - standard system utilities (`cp`, `mkdir`)
+
 ## Bugs and feature requests
 
 Please send bug requests and feature reports to `tech(at)occrp.org`.