The phrase "HO HO HO" is often associated with Christmas and is commonly used as Santa Claus's iconic laugh. It is typically written in all capital letters and can be used to convey a festive and jolly atmosphere. In html, the code for the phrase would be , which would display it in large, bold letters. The "12x4.5in" part may refer to the size of the text, where 12 inches would be the width and 4.5 inches would be the height. The "in" could also stand for "inches" as a unit of measurement. Overall, the phrase would look like this: