Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Team | Outgoing manager | Manner of departure | Date of vacancy | Replaced by | Date of appointment |
| --- | --- | --- | --- | --- | --- |
| VfR Aalen | Edgar Schmitt | Sacked | 27 August 2008 | Jürgen Kohler | 28 August 2008 |
| FC Carl Zeiss Jena | Henning Bürger | Sacked | 14 September 2008 | René van Eck | 22 September 2008 |
| Stuttgarter Kickers | Stefan Minkwitz | Sacked | 21 September 2008 | Edgar Schmitt | 21 September 2008 |
| VfR Aalen | Jürgen Kohler | Resigned | 15 November 2008 | Petrik Sander | 21 November 2008 |
| SSV Jahn Regensburg | Thomas Kristl | Sacked | 24 November 2008 | Markus Weinzierl | 24 November 2008 |
| Wuppertaler SV Borussia | Christoph John | Sacked | 22 December 2008 | Uwe Fuchs | 23 December 2008 |
| FC Carl Zeiss Jena | René van Eck | Sacked | 23 March 2009 | Marc Fascher | 23 March 2009 |
| Stuttgarter Kickers | Edgar Schmitt | Resigned | 14 April 2009 | Rainer Kraft | 14 April 2009 |
| SV Wacker Burghausen | Günter Güttler | Sacked | 15 April 2009 | Ralf Santelli (interim) | 15 April 2009 |
| FC Rot-Weiß Erfurt | Karsten Baumann | Sacked | 28 April 2009 | Henri Fuchs (interim) | 28 April 2009 |
| VfR Aalen | Petrik Sander | Resigned | 5 May 2009 | Rainer Scharinger | 6 May 2009 |
Question:
What was the manner in which Petrik Sander departed?
Answer:
Resigned