The following is from thewestminsterstandard.org:
Q. 51. What is forbidden in the second commandment?
A. The second commandment forbiddeth the worshipping of God by images, or any other way not appointed in his Word.
Q. 52. What are the reasons annexed to the second commandment?
A. The reasons annexed to the second commandment are, God’s sovereignty over us, his propriety in us, and the zeal he hath to his own worship.
Q. 53. Which is the third commandment?
A. The third commandment is, Thou shalt not take the name of the Lord thy God in vain: for the Lord will not hold him guiltless that taketh his name in vain.
Q. 54. What is required in the third commandment?
A. The third commandment requireth the holy and reverent use of God’s names, titles, attributes, ordinances, word, and works.
Q. 55. What is forbidden in the third commandment?
A. The third commandment forbiddeth all profaning or abusing of anything whereby God maketh himself known.