diff --git a/README.md b/README.md
index 7d17d55..d44001b 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,7 @@
 not available in the PHP release version you use, you can fallback to
 `avifinfo.php` instead.
 
-See `avifinfo_test.php` for a usage example.
+See `tests/avifinfo_test.php` for a usage example.
 
 ### PHP test
 
diff --git a/avifinfo.c b/avifinfo.c
index 599c019..5d7ec78 100644
--- a/avifinfo.c
+++ b/avifinfo.c
@@ -372,7 +372,7 @@
         (!memcmp(box->type, "infe", 4) && box->version >= 2 &&
          box->version <= 3);
     // Instead of considering this file as invalid, skip unparsable boxes.
-    if (!is_parsable) memcpy(box->type, "\0skp", 4);  // \0 so not a valid type
+    if (!is_parsable) memcpy(box->type, "skip", 4);  // FreeSpaceBox
   }
   AVIF_DEBUG_LOG("%*c", nesting_level * 2, ' ');
   AVIF_DEBUG_LOG("Box type %.4s size %d\n", box->type, box->size);
diff --git a/avifinfo.h b/avifinfo.h
index 0a558f0..bc17df1 100644
--- a/avifinfo.h
+++ b/avifinfo.h
@@ -35,7 +35,7 @@
 } AvifInfoStatus;
 
 typedef struct {
-  uint32_t width, height;   // In number of pixels. Ignores mirror and rotation.
+  uint32_t width, height;   // In number of pixels. Ignores crop and rotation.
   uint32_t bit_depth;       // Likely 8, 10 or 12 bits per channel per pixel.
   uint32_t num_channels;    // Likely 1, 2, 3 or 4 channels:
                             //   (1 monochrome or 3 colors) + (0 or 1 alpha)
diff --git a/avifinfo.php b/avifinfo.php
index 81269ec..dfb67c3 100644
--- a/avifinfo.php
+++ b/avifinfo.php
@@ -103,7 +103,7 @@
   public $primary_item_id;
   public $primary_item_features = array( // Deduced from the data below.
     'width'        => UNDEFINED, // In number of pixels.
-    'height'       => UNDEFINED, // Ignores mirror and rotation.
+    'height'       => UNDEFINED, // Ignores crop and rotation.
     'bit_depth'    => UNDEFINED, // Likely 8, 10 or 12 bits per channel per pixel.
     'num_channels' => UNDEFINED  // Likely 1, 2, 3 or 4 channels:
                                           //   (1 monochrome or 3 colors) + (0 or 1 alpha)
@@ -303,7 +303,7 @@
                      ( $this->type == 'auxC' && $this->version <= 0 );
       // Instead of considering this file as invalid, skip unparsable boxes.
       if ( !$is_parsable ) {
-        $this->type = 'unknownversion';
+        $this->type = 'skip'; // FreeSpaceBox. To be ignored by readers.
       }
     }
     // print_r( $this ); // Uncomment to print all boxes.