Before creating standard, you must created the Admin Mode
1) Open the CATIA Admin Mode
2) Then go to ‘Tools>>Standards’.
3) Choose the Category as drafting. Choose the type of standard that you want to edit, example above ISO.xml
5) Example to change the paper size. Go to Styles>>Sheet>>A0 ISO.
6) Here you may change the paper size by entering you new dimension in the box shown.
7) Click Save As New and give a new name example “New Standard”. This is to prevent from override the previous ISO standard.
8) When you want to open a New Drawing file, you may choose the previous customize standard that you created.
9) For an Existing Drawing file, go to File>>Page Setup. Then select the previous customize standard that you created and click Update.