Noun. 1. orthoclase-a white or colored monoclinic feldspar. feldspar, felspar-any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium.rÂ·thoÂ·clase. A type of feldspar consisting of potassium aluminum silicate. Orthoclase is typically white, pink, yellow, or brown, but it can also be colorless. It is especially common in igneous rocks.
Year of Assessment. 'Year of Assessment' (YA) refers to the year in which income tax is calculated and charged. The assessment is for the income earned in the preceding year, starting on 1 Jan and ending on 31 Dec. Example: For YA 2017, the assessment is for income earned from Jan to Dec 2016. Back to top.
Audit and Assessment â Three Years IRS, Four Years FTB. The IRS has a three-year limitation period on assessment from the time of the returnâs filing. That means that if three years pass from the time you, the taxpayer, filed your return, the IRS can no longer audit you for that tax year.