Another thing to consider, depending on how that custom dimension is being set, could be bot traffic...
Device Types are also encoded as part of the user agent string... often bots won't have this.. in Adobe's standard device type, I believe they convert this to something like "unknown"... but in your case, it could just be sending no value...
Since 'Device Type (v53)' is a Custom Conversion variable the Unspecified breakdown line means no v53 value was set or persisting at the time when applied against Direct Marketing Channel in this time period. It looks like your coverage for dimension 'Device Type (v53)' which is custom set for your implementation as you broke it down by the provided Operating System Types may not be set in largely Desktop PC Windows scenarios.
“Unspecified” is a fairly common line item in reports. It is also frequently referred to as “None”.
An event fires without a conversion variable:For example, a user comes to your site and makes a purchase without any eVar1 value. If you view orders using the eVar1 dimension, there is no value to attribute this order to. Therefore, it is automatically attributed to “Unspecified”.
Another thing to consider, depending on how that custom dimension is being set, could be bot traffic...
Device Types are also encoded as part of the user agent string... often bots won't have this.. in Adobe's standard device type, I believe they convert this to something like "unknown"... but in your case, it could just be sending no value...
