diff --git a/doc/index.rst b/doc/index.rst
index 4b67ac6..be55a69 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -288,26 +288,38 @@ Standard properties
 The :mod:`openslide` module provides attributes containing the names of
 some commonly-used OpenSlide properties.
 
-.. data:: PROPERTY_NAME_COMMENT
+.. data:: PROPERTY_NAME_BACKGROUND_COLOR
 
-   The name of the property containing a slide's comment, if any.
+   The name of the property containing a slide's background color, if any.
+   It is represented as an RGB hex triplet.
 
-.. data:: PROPERTY_NAME_VENDOR
+.. data:: PROPERTY_NAME_BARCODE
 
-   The name of the property containing an identification of the vendor.
+   The name of the property containing a slide's barcode, if any.
 
-.. data:: PROPERTY_NAME_QUICKHASH1
+.. data:: PROPERTY_NAME_BOUNDS_HEIGHT
 
-   The name of the property containing the "quickhash-1" sum.
+   The name of the property containing the height of the rectangle bounding
+   the non-empty region of the slide, if available.
 
-.. data:: PROPERTY_NAME_BACKGROUND_COLOR
+.. data:: PROPERTY_NAME_BOUNDS_WIDTH
 
-   The name of the property containing a slide's background color, if any.
-   It is represented as an RGB hex triplet.
+   The name of the property containing the width of the rectangle bounding
+   the non-empty region of the slide, if available.
 
-.. data:: PROPERTY_NAME_OBJECTIVE_POWER
+.. data:: PROPERTY_NAME_BOUNDS_X
 
-   The name of the property containing a slide's objective power, if known.
+   The name of the property containing the X coordinate of the rectangle
+   bounding the non-empty region of the slide, if available.
+
+.. data:: PROPERTY_NAME_BOUNDS_Y
+
+   The name of the property containing the Y coordinate of the rectangle
+   bounding the non-empty region of the slide, if available.
+
+.. data:: PROPERTY_NAME_COMMENT
+
+   The name of the property containing a slide's comment, if any.
 
 .. data:: PROPERTY_NAME_MPP_X
 
@@ -319,25 +331,17 @@ some commonly-used OpenSlide properties.
    The name of the property containing the number of microns per pixel in
    the Y dimension of level 0, if known.
 
-.. data:: PROPERTY_NAME_BOUNDS_X
-
-   The name of the property containing the X coordinate of the rectangle
-   bounding the non-empty region of the slide, if available.
-
-.. data:: PROPERTY_NAME_BOUNDS_Y
+.. data:: PROPERTY_NAME_OBJECTIVE_POWER
 
-   The name of the property containing the Y coordinate of the rectangle
-   bounding the non-empty region of the slide, if available.
+   The name of the property containing a slide's objective power, if known.
 
-.. data:: PROPERTY_NAME_BOUNDS_WIDTH
+.. data:: PROPERTY_NAME_QUICKHASH1
 
-   The name of the property containing the width of the rectangle bounding
-   the non-empty region of the slide, if available.
+   The name of the property containing the "quickhash-1" sum.
 
-.. data:: PROPERTY_NAME_BOUNDS_HEIGHT
+.. data:: PROPERTY_NAME_VENDOR
 
-   The name of the property containing the height of the rectangle bounding
-   the non-empty region of the slide, if available.
+   The name of the property containing an identification of the vendor.
 
 
 Exceptions
diff --git a/openslide/__init__.py b/openslide/__init__.py
index 2683b9f..0be9a78 100644
--- a/openslide/__init__.py
+++ b/openslide/__init__.py
@@ -44,17 +44,18 @@
 
 __library_version__ = lowlevel.get_version()
 
-PROPERTY_NAME_COMMENT = 'openslide.comment'
-PROPERTY_NAME_VENDOR = 'openslide.vendor'
-PROPERTY_NAME_QUICKHASH1 = 'openslide.quickhash-1'
 PROPERTY_NAME_BACKGROUND_COLOR = 'openslide.background-color'
-PROPERTY_NAME_OBJECTIVE_POWER = 'openslide.objective-power'
-PROPERTY_NAME_MPP_X = 'openslide.mpp-x'
-PROPERTY_NAME_MPP_Y = 'openslide.mpp-y'
+PROPERTY_NAME_BARCODE = 'openslide.barcode'
+PROPERTY_NAME_BOUNDS_HEIGHT = 'openslide.bounds-height'
+PROPERTY_NAME_BOUNDS_WIDTH = 'openslide.bounds-width'
 PROPERTY_NAME_BOUNDS_X = 'openslide.bounds-x'
 PROPERTY_NAME_BOUNDS_Y = 'openslide.bounds-y'
-PROPERTY_NAME_BOUNDS_WIDTH = 'openslide.bounds-width'
-PROPERTY_NAME_BOUNDS_HEIGHT = 'openslide.bounds-height'
+PROPERTY_NAME_COMMENT = 'openslide.comment'
+PROPERTY_NAME_MPP_X = 'openslide.mpp-x'
+PROPERTY_NAME_MPP_Y = 'openslide.mpp-y'
+PROPERTY_NAME_OBJECTIVE_POWER = 'openslide.objective-power'
+PROPERTY_NAME_QUICKHASH1 = 'openslide.quickhash-1'
+PROPERTY_NAME_VENDOR = 'openslide.vendor'
 
 _T = TypeVar('_T')