That columns which have under 4 anchor bolts are now illegal according to OSHA's New Subpart R Steel Erection Standard? Less than 4 anchor bolts is still legal for POSTS ONLY. The OSHA definition for columns and posts is as follows:

Column means a load-carrying vertical member that is part of the primary skeletal framing system. Columns do not include posts.

Post means a structural member with a longitudinal axis that is essentially vertical, that: (1) weighs 300 pounds or less and is axially loaded (a load presses down on the top end), or (2) is not axially loaded, but is laterally restrained by the above member. Posts typically support stair landings, wall framing, mezzanines and other substructures.

Also, the anchor bolts that support the column must be strong enough to allow for an erector to lean a ladder onto it for connection purposes. The OSHA standards say this about anchorage strength:

Each column anchor rod (anchor bolt) assembly, including the column-to-base plate weld and the column foundation, shall be designed to resist a minimum eccentric gravity load of 300 pounds (136.2 kg) located 18 inches (.46m) from the extreme outer face of the column in each direction at the top of the column shaft.