Daylight Opening (DLO) means the "guts" of the unit fit between the posts and the flange overlaps either the outside or the inside face of the post. In EZE-Breeze language your “Daylight Opening” is your Rough Opening, from which cutbacks (deducts) will be taken.
Cutbacks/Deducts mean the amount of "play" the finished units will have between your posts. Outside mount units can have a standard 1/8" cutback (which allows for 1/8" of "play" between the unit and your framing) or an optional 1/4" cutback (for 1/4" of "play"). Inside mount units have a 3/8" cutback only. Windows are supposed to be a tight fit between your posts.
Note: The DLO measurement does not include the flange. Edge of flange to edge of flange will be approx 2" wider than the Daylight Opening size. The flange is what you screw through to attach the window to the posts.
Make Size/Actual Size means that you have already applied cutbacks to your dimensions, and the measurements you have provided are the exact sizes of the units that you want built, not including the flange.
TIP-to-TIP (TTT) sizing means you are ordering the windows so the entire frame including the flange fits between your posts. In those cases, you will need a stop for the flange to be applied to that is a minimum of ¾" wide.
REMEMBER: These units are designed so you need no interior trimming between the framing and the unit. Normally a thin bead of caulking after installation is all that is needed. Note, you can trim out with quarter round or other trim to match your style. In any case, you will center the unit evenly within the opening, making sure that it's level and square.
NOTE: Once orders are put into production, they can not be changed or cancelled. You will own the windows . So remember “measure twice, and you will only have to order once”.