LLC, LC, Ltd. Co., Limited Liability Company: a form of business whose owners enjoy limited liability, but which is not a corporation. Allowable abbreviations vary by state. Note that in some states Ltd. by itself is not a valid abbreviation for an LLC, because in some states (e.g. Texas), it may denote a corporation instead. See also Series LLC. For U.S. federal tax purposes, in general, an LLC with two or more members is treated as a partnership, and an LLC with one member is treated as a sole proprietorship.
PLLC, Professional Limited Liability Company: some states do not allow certain professionals to form an LLC that would limit the liability that results from the services professionals provide such as doctors, medical care; lawyers, legal advice; and accountants, accounting services; architects, architectural services; when the company formed offers the services of the professionals. Instead those states allow a PLLC or in the LLC statutes, the liability limitation only applies to the business side, such as creditors of the company, as opposed to the client/customer service side, the level of medical care, legal services, or accounting provided to clients. This is meant to maintain the higher ethical standards that these professionals have committed themselves to by becoming licensed in their profession and to prevent them from being immune (or at least limit their immunity) to malpractice suits.
Where the equipment you use in your business was acquired as a gift, you may report your estimate of its current market value on the Business Property Statement (that is, what you think it would sell for in the open market place). Enter that estimated value in the most current year's cost line and add a note indicating that the entry is an estimate.