deletions | additions       diff --git a/background.md b/background.md  index b39d3e9..8885cb2 100644  --- a/background.md  +++ b/background.md 
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* [ePub OCF format](http://idpf.org/epub/30/spec/epub30-ocf-20111011.html)  * [ODF bundle](https://researchobject.github.io/specifications/bundle/)  * [Adobe UCF](https://wikidocs.adobe.com/wiki/display/PDFNAV/Universal+Container+Format)  * [SHIWA](http://www.shiwa-workflow.eu/] IWIR] IWIR  * .. not in cronological order :)