1 files changed, 9 insertions, 0 deletions
diff --git a/pdf.md b/pdf.md
index f13af21..7cc5cf0 100644
--- a/pdf.md
+++ b/pdf.md
@@ -4,6 +4,11 @@
 
     gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=out.pdf in1.pdf in2.pdf
 
+GhostScript uses some algorithm to autodetect page orientation, and may
+undersireably flip some pages. To disable this, add:
+
+    "-dAutoRotatePages=/None"
+
 ## Compress
 
     gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/default -dNOPAUSE -dQUIET -dBATCH -dDetectDuplicateImages -dCompressFonts=true -r150 -sOutputFile=output.pdf input.pdf
@@ -12,6 +17,10 @@
 
     pdfjam --outfile out.pdf in.pdf 1,3,4-7
 
+`--landscape` to set orientation of output pages.
+
+`--angle <angle>` to rotate (counter clockwise).
+
 ## Images to pdf
 
     convert in1.jpg in2.jpg out.pdf