I have a 98 cherokee and I have the same warning light that comes and goes. My manual that came with the Jeep doesn't have a section for warning lights (Its an Automotive Repair Manual... Not sure if thats why)
My concern is that it doesn't seem to have anything to do with windshield washing levels as it seems to come on and off when my vehicle is making a burning plastic smell that comes and goes with the light. At some point through my searching of Jeep Cherokee warning lights online I managed to come across that icon but sideways instead of up and down and it said something to do with blockage. Have an appointment to go and get an oil change and I don't think that this model has a cabin air filter so I'm not sure what could be causing the issue.