I found this tip accidentally which may already published in WPCentral.
OneNote app for WP 8.1 is not attractive for most of the user especially those who came from Android and IPhone cause there's no much options available on the WP8/8.1 app to organize/ categorize the notes directly from smart phone as you can add the note only in Quick Notes section . However once you login to OneNote through your PC web browser, there you would find option to add the section , even you can associate the color with it. Now open the app on your WP and you would find the new section added as well. I,e You added via browser New section named as "Poetry" . This new section would also visible also over WP8 app where you can add the notes related to poetry which is very handy to organize the notes within smartphone app.
OneNote app for WP 8.1 is not attractive for most of the user especially those who came from Android and IPhone cause there's no much options available on the WP8/8.1 app to organize/ categorize the notes directly from smart phone as you can add the note only in Quick Notes section . However once you login to OneNote through your PC web browser, there you would find option to add the section , even you can associate the color with it. Now open the app on your WP and you would find the new section added as well. I,e You added via browser New section named as "Poetry" . This new section would also visible also over WP8 app where you can add the notes related to poetry which is very handy to organize the notes within smartphone app.