diff --git a/common/lib/capa/eia.py b/common/lib/capa/eia.py
index bc962312ec..362dc33a2d 100644
--- a/common/lib/capa/eia.py
+++ b/common/lib/capa/eia.py
@@ -1,3 +1,6 @@
+""" Standard resistor codes.
+http://en.wikipedia.org/wiki/Electronic_color_code
+"""
 E6=[10,15,22,33,47,68]
 E12=[10,12,15,18,22,27,33,39,47,56,68,82]
 E24=[10,12,15,18,22,27,33,39,47,56,68,82,11,13,16,20,24,30,36,43,51,62,75,91]