Textual format SIF http://wiki.cytoscape.org/GettingStarted and http://wiki.cytoscape.org/Cytoscape_User_Manual/Network_Formats, accessed 20 June 2012 Allyson Lister SIF stands for Simple Interaction Format, and is a text format invented for Cytoscape. If the file contains any tab characters, then tabs are used to delimit the fields and spaces are considered part of the name. If the file contains no tabs, then any spaces are delimiters that separate names (and names cannot contain spaces).