I've uncovered some older rulings (and a couple things I noticed while typing them up) that were not incorporated into the current printing. I'm enclosing them here in a single post for convenience's sake. They will appear in the next major TacOps errata revision (3.1). All references are to the PDF, 3rd release:
pp. 18-19, Evading (Movement Mode)
Add a clarifying note that, despite the 'Mech-centric nature of the text, any unit that has Running or Flanking MP can use Evading. In addition, a unit does not have to run/flank to evade (it can just walk/cruise, and would also generate less heat as a result).
p. 32, Expanded Movement Costs
Add footnote 24 to "Sand"
p. 33
Note to self, move the #6 footnote up to p. 32.
p. 35, Expanded Movement Costs
Add footnote 23 to "Torrent"
p. 44, Fire Tables
"§Except under the following conditions: in Vacuum and Trace Atmospheric Pressures and in Tornado F1-F3 and Tornado F4+, no fire is possible. For Castles Brian hexes, fire is not automatic; instead, divide the standard Heavy and Hardened modifiers in half (round down) and apply a +2 modifier when making the roll to start a fire."
Change to:
"§Except under the following conditions: in Vacuum and Trace Atmospheric Pressures and in Tornado F1-F3 and Tornado F4+, no fire is possible. For Castles Brian hexes, fire is not automatic; instead, divide the standard Heavy and Hardened modifiers in half (round down) and apply a +2 modifier when making the roll to start a fire. Otherwise, any hex (whether water, clear and so on) struck by any of these munitions is automatically on fire. Do not check for weather conditions extinguishing fires in the turn they are started by these munitions. At the start of the following turn, however, they are treated as a standard fire; meaning that such a fire in a Water or Clear hex would be extinguished at the end of that turn."
p. 50, Ice
"Every time a unit enters a hex not using careful movement (see p. 63)"
Change to:
"Every time a unit enters an ice-coated hex not using careful movement (see p. 63)"
p. 51, Swamp, Quicksand
"During every End Phase after the turn in which the swamp hex becomes a quicksand hex, the unit will sink 1 level; apply a +3 modifier to the Piloting Skill Roll to get unstuck from a quicksand hex, as well as a cumulative +3 modifier for each level under the surface."
Change to:
"During every End Phase after the turn in which the swamp hex becomes a quicksand hex, the unit will sink 1 level (treat 'Mechs one level down as in partial cover; they are unable to fire any leg-mounted weapons). Apply a +3 modifier to the Piloting Skill Roll to get unstuck from a quicksand hex, as well as a cumulative +3 modifier for each level under the surface."
p. 57, Fog
Change both references to Careful Movement from "p. 62" to "p. 63"
p. 62, Bog Down Rules
"Jump-capable units that use Walking or Running movement to enter tundra, magma, deep snow or mud may get stuck,"
Change to:
"Jump-capable units that use Walking or Running movement to enter sand, tundra, liquid magma, deep snow or mud may get stuck,"
p. 62, Bog Down Rules
"Additional Modifiers: For tundra, magma crust, deep snow and mud hexes,"
Change to:
"Additional Modifiers: For tundra, deep snow and mud hexes,"
p. 63, Careful Movement, fourth paragraph, last sentence
"In all other terrain, the crash ends the vehicle’s movement, and the vehicle sustains damage to its Front side as if it had charged."
Change to:
"In all other terrain, the crash ends the vehicle’s movement, and the vehicle sustains damage to its Front side as if it had charged an identical unit to itself."
p. 63, Careful Movement, fourth paragraph, last sentence
"If both fog and ice are present, the modifiers are cumulative,"
Change to:
"If both fog and ice are present, the movement modifiers are cumulative,"
p. 64, Careful Movement
Between "Hover and WiGE Vehicles" and "Terrain Factor", add a new subsection: "ProtoMechs"
"ProtoMechs use their Gunnery Skill to check when moving through a hex at full speed. Treat a ProtoMech like a vehicle if it fails."
p. 105, Heat Sink Coolant Failure
Change this section's name to "Heat Sink Coolant Failure ('Mechs Only)"
p. 221, Visual Range Tables
Move Gusting Rain up to the same row as Heavy Rain. Also, add Torrential Downpour and Ice Storm to the Heavy Rain row (and delete the extra space between the slash and Blowing Sand)
p. 221, Sensor Spotting, third paragraph
"A result of 7 or 8 means the sensor detects any unit within its short range. A result of 5 or 6 means the sensor detects units out to its medium range. A result of 2 to 4 means the sensor detects units out to its long range."
Change to:
"A result of 7 or 8 means the sensor detects any unit within its short range band. A result of 5 or 6 means the sensor detects units within its medium range band. A result of 2 to 4 means the sensor detects units within its long range band."
p. 222, Infrared Sensors
"add 1 additional hex if the unit has been hit by an inferno attack, or is standing in a hex that is on fire."
Change to:
"add 1 additional hex if the unit has been hit by an inferno attack in the last turn, or is standing in a hex that is on fire."
p. 222, Infrared Sensors, last paragraph
"Units that are not “hot” cannot be detected by an IR sensor scan."
Change to:
"Units that are not “hot” (i.e. those without one or more heat points on a Heat Scale) cannot be detected by an IR sensor scan."
p. 224, Change "Undewater Combat" to "Underwater Combat"