The HCSB Study Bible notes:
The certificate of debt may refer to a handwritten document or to the Mosaic law. Paul typically viewed the law’s purpose as revealing the guilt of sinners (Dt 27:26; Rm 7:13; 1Co 15:56; Gal 3:10). Some Jewish writings, likewise, speak of God keeping records of people’s sins as debts against them. God, however, has abolished those records through Christ’s substitutionary atonement that was accomplished when He died on the cross.
This passage does not refer to the abrogation of the whole law, rather to the abrogation of condemnation brought by the law and that which was not inherently moral. This is seen in the close connection that one should have in interpreting this text and Ephesians 2:15. Why? Because these are the only two places where Paul uses the word δόγμα (dogma, G1378) which is defined as “a decree, statue, ordinance” and is used in Luke 2:1; Acts 16:4; 17:7; Ephesians 2:15 and Colossians 2:14. Dogma is only used twice by Paul and therefore the meaning should be gleaned from the context of its uses. I believe that it is clear from Ephesians 2 that what the apostle is speaking about when he says “abolishing the law of commandments expressed in ordinances” is the ceremonial law which had set Israel apart from the Gentile nations and not the moral law which is on the heart of every man. Therefore, in Colossians 2:14, the reference is not to the moral, but ceremonial law, as Calvin notes and Paul’s further discussion will lead to. Therefore, these things which had set Israel apart and were against us were nailed to the cross and done away with. It is on this basis that the apostle concludes (v. 16, “Therefore”) that no one is to judge Christians about foods or festivals. Because they were nailed to the cross and were abolished (Eph. 2:15), there is no longer a moral obligation to observe them. The same God Who by positive precept commanded them has abolished and abrogated them because they were fulfilled in Christ.
Albert Barnes observes on the first part of v. 14:
Blotting out the handwriting - The word rendered handwriting means something written by the hand, a manuscript; and here, probably, the writings of the Mosaic law, or the law appointing many ordinances or observances in religion. The allusion is probably to a written contract, in which we bind ourselves to do any work, or to make a payment, and which remains in force against us until the bond is cancelled. That might be done, either by blotting out the names, or by drawing lines through it, or, as appears to have been practiced in the East, by driving a nail through it. The Jewish ceremonial law is here represented as such a contract, binding those under it to its observance, until it was nailed to the cross. The meaning here is, that the burdensome requirements of the Mosaic law are abolished, and that its necessity is superseded by the death of Christ. His death had the same effect, in reference to those ordinances, as if they had be...