1 files changed, 1 insertions, 0 deletions

diff --git a/docs/posix_conformance.txt b/docs/posix_conformance.txt
index 0e6f4a317..f6e8858cc 100644
--- a/docs/posix_conformance.txt
+++ b/docs/posix_conformance.txt
@@ -183,6 +183,7 @@ dd compatibility options:
   iflag=skip_bytes|  yes   |           |
   iflag=fullblock |  yes   |           |
   oflag=seek_bytes|  yes   |           |
+  oflag=append    |  yes   |           |
 
 df POSIX options
  option           | exists | compliant | remarks