Possible Clues:

• Landlord's worrying silence over second instalment of rent
• Permit Oriental seller of alcohol
• Troubled client stopped short to meet landlord
• One able to sell alcohol
• Person with official permit to sell, say, drink
• Uncommonly nice — else who would be a publican?
• Large cubes seen floating about in drink he supplies?
• Seen with lice running wild, Lassie for one has the right papers
• Suckers seen working for landlord
• Software user, at times