just:in multi exposes a variety of internal system variable keys to ease up metadata processing. These are divided into capture related and general keys. The following table lists them accordingly.

System Variable Keys (Capture Section)	Description
%Just_In_Container	Will be replaced by one of the following values: “QuickTime”,”MXF GC”, ”MXF D-10”, ”MXF XDCAM”, ”Avid OP-Atom”, “AVFoundation QuickTime”, “AVFoundation MP4”.
%Just_In_Timecode_Source	Will be replaced by one of the following values: “Computer Time”, ”VTR - RS-422”, ”VTR FireWire”, ”LTC over Audio”,”Miranda Little Red”,”Capture card LTC”,”SDI Embedded”.
%Just_In_Framerate	Will be replaced by one of the following values: “23.976”, “24”, “25”, “29.97”, “30”, “50”, “59.94”, “60”.
%Just_In_Aspect_Ratio	Will be replaced by one of the following values: “4:3”, “16:9”.
%Just_In_Capture_Codec	Will be replaced by the codecs full name.
%Just_In_Audio_Channels	Will be replaced with the actual number of audio channels writing into the container: “2”, “4”, “8” or “16”.
%Just_In_Capture_Resolution	Will be replaced by the resolution of the target format. E.g. “1920x1080”, “720x486”.
%Just_In_Capture_Width	Will be replaced by the capture width. E.g. “1920”.
%Just_In_Capture_Height	Will be replaced by the capture height. E.g. “486”.

The general keys exposed by just:in multi are listed in the following:

System Variable Keys (General)	Description
%Just_In_Capture_Split	Will be replaced by one of the following values: “0” - no split occurred, “1” - a split occurred, “2” - last clip of the split sequence.
%Just_In_Previous_Split_Reference_Clip	Will be replaced by the filename of the clip previous to the one currently recording. Empty string if no split occurred.
%Just_In_Capture_Duration	Will be replaced by the length of the recording in “standard time”. E.g. “00:30:00” - 30 minutes.
%Just_In_Capture_Inpoint	Will be replaced by the Inpoint timecode. This is the timecode of the first frame. E.g. "10:00:00:00’.
%Just_In_Capture_Outpoint	Will be replaced by the Outpoint timecode. This is the timecode of the last frame. E.g. "11:00:00:00".
%Just_In_Clipname	Will be replaced by the Clipname with extension. E.g. "sample.mov".
%Just_In_Full_Clipname	Will be replaced by the full clipname. E.g. “/path/to/ the/movie.mov”.
%Just_In_Custom_Date	Will be replaced by a representation of the keys’ value. E.g “%d/%m/%Y %H:%M:%S” will be replaced by 01/01/2011 15:32:53.

Every field of the naming convention is available for metadata processing - so just use the same key as in the naming convention. There’s one special case though:

Naming Convention	Description
%Name (or any custom variable)	Will be replaced by the contents of the “Name” field (or any custom fields) of the “Clip” section. In Schedule mode this field will be the name as the one in the Apple Calendar event.