CLA is an acronym for Common Level of Assessment or Common Level of Appraisal

What is the purpose of the CLA? The following is from the State of Vermont

What is the purpose of the common level of appraisal? The adjustment by the common level of appraisal (CLA) ensures that you and your neighbor in the next town pay a reasonable comparable of education tax on properties of equal value. The (CLA) is used to equalize education taxes statewide by reflecting local variations that occur based on reappraisal schedules and other factors. Example: Let’s say you have a camp in East Overshoe that is worth $100,000. Your listers did a complete reappraisal for tax year 2012 and they’ve assessed you at $100,000. There’s a camp across the town line in West Overshoe that is also worth $100,000. The Town of West Overshoe is planning to reappraise for tax year 2017, but for tax year 2015 that camp is assessed at $85,000. Without the CLA, you would be taxed at the same $1.515 tax rate. You would pay $1,515.00 Your West Overshoe neighbor would pay 1,287.75. With the CLA, you should both pay approximately the same amount. It is useful to think of the CLA as adjusting the listed value of the property to fair market value to ensure fairness. The West Overshoe camp is adjusted by the common level of appraisal to bring its listed value into line with the market. Let’s assume West Overshoe’s CLA of 85.00% and East Overshoe’s CLA is 100.00% (Assessed Value) $85,000 ÷ (CLA) .85 = (Adjusted Value) $100,000. Now the taxes paid by the two camps would be approximately the same.

How is the CLA determined?  Link to PVR's guide