diff --git a/pyexiv2/reference.py b/pyexiv2/reference.py
deleted file mode 100644
index 8f78915..0000000
--- a/pyexiv2/reference.py
+++ /dev/null
@@ -1,29 +0,0 @@
-# These tags are used by Windows and encoded in UCS2.
-# pyexiv2 will automatically convert encoding formats when reading and writing them.
-EXIF_TAGS_ENCODED_IN_UCS2 = [
-    'Exif.Image.XPTitle',
-    'Exif.Image.XPComment',
-    'Exif.Image.XPAuthor',
-    'Exif.Image.XPKeywords',
-    'Exif.Image.XPSubject',
-]
-
-# These tags can be written repeatedly, so there may be multiple values.
-# pyexiv2 will convert their values to a list of strings.
-IPTC_TAGS_REPEATABLE = [
-    'Iptc.Envelope.Destination',
-    'Iptc.Envelope.ProductId',
-    'Iptc.Application2.ObjectAttribute',
-    'Iptc.Application2.Subject',
-    'Iptc.Application2.SuppCategory',
-    'Iptc.Application2.Keywords',
-    'Iptc.Application2.LocationCode',
-    'Iptc.Application2.LocationName',
-    'Iptc.Application2.ReferenceService',
-    'Iptc.Application2.ReferenceDate',
-    'Iptc.Application2.ReferenceNumber',
-    'Iptc.Application2.Byline',
-    'Iptc.Application2.BylineTitle',
-    'Iptc.Application2.Contact',
-    'Iptc.Application2.Writer',
-]