There was no tax called 'Rinjizoyaku,' but the word was used to refer collectively to taxation in the form of forced labor imposed on the people in the name of 'dairizatsuji' (miscellaneous chores in the palace), 'cho no kobai kinu' (acquisition and purchase of silk), etc.
「臨時雑役」という名称の租税が存在したわけではなく、「内裏雑事」「調沽買絹」などの名目で課された個々の賦課を一括する際に用いられた語である。