From eaf4f21ce65081da0490a41ee1829b4ec8319109 Mon Sep 17 00:00:00 2001
From: jaseg <git@jaseg.de>
Date: Thu, 3 Feb 2022 19:57:16 +0100
Subject: More doc

---
 docs/utilities.rst | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

(limited to 'docs/utilities.rst')

diff --git a/docs/utilities.rst b/docs/utilities.rst
index 80ce5ec..5e75df5 100644
--- a/docs/utilities.rst
+++ b/docs/utilities.rst
@@ -1,8 +1,23 @@
 Utilities
 =========
 
+Physical units
+~~~~~~~~~~~~~~
+
+Gerbonara tracks length units using the :py:class:`.LengthUnit` class. :py:class:`.LengthUnit` contains a number of
+conventient conversion functions. Everywhere where Gerbonara accepts units as a method argument, it automatically
+converts a string ``'mm'`` or ``'inch'`` to the corresponding :py:class:`.LengthUnit`.
+
 .. autoclass:: gerbonara.utils.LengthUnit
    :members:
 
+Format settings
+~~~~~~~~~~~~~~~
+
+When reading or writing Gerber or Excellon, Gerbonara stores information about file format options such as zero
+suppression or number of decimal places in a :py:class:`.FileSettings` instance. When you are writing a Gerber file,
+Gerbonara picks reasonable defaults, but allows you to specify your own :py:class:`.FileSettings` to override these
+defaults.
+
 .. autoclass:: gerbonara.cam.FileSettings
    :members:
-- 
cgit