Unfortunately codes are not written by wordsmiths. Often, IMO, the code proposals are not thoroughly thought out before being submitted. Additionally, a lot of code gets written on the fly in the hallway at the hearings as multiple parties try to keep their ox from getting gored. Never a good situation.
Here is an example of either / or:
R308.4.2 Glazing adjacent to doors.
Glazing in an individual fixed or operable panel adjacent to a door shall be considered to be a hazardous location
where the bottom exposed edge of the glazing is less than 60 inches (1524 mm) above the floor or walking surface and
it meets either of the following conditions:
1. Where the glazing is within 24 inches (610 mm) of either side of the door in the plane of the door in a closed
position.
2. Where the glazing is on a wall perpendicular to the plane of the door in a closed position and within 24 inches (610
mm) of the hinge side of an in-swinging door.
Here's an example of conditional:
R308.4.3 Glazing in windows.
Glazing in an individual fixed or operable panel that meets all of the following conditions shall be considered to be a
hazardous location:
1. The exposed area of an individual pane is larger than 9 square feet (0.836 m2),
2. The bottom edge of the glazing is less than 18 inches (457 mm) above the floor,
3. The top edge of the glazing is more than 36 inches (914 mm) above the floor; and
4. One or more walking surfaces are within 36 inches (914 mm), measured horizontally and in a straight line, of the
glazing.
Here is an example of either / or:
R308.4.2 Glazing adjacent to doors.
Glazing in an individual fixed or operable panel adjacent to a door shall be considered to be a hazardous location
where the bottom exposed edge of the glazing is less than 60 inches (1524 mm) above the floor or walking surface and
it meets either of the following conditions:
1. Where the glazing is within 24 inches (610 mm) of either side of the door in the plane of the door in a closed
position.
2. Where the glazing is on a wall perpendicular to the plane of the door in a closed position and within 24 inches (610
mm) of the hinge side of an in-swinging door.
Here's an example of conditional:
R308.4.3 Glazing in windows.
Glazing in an individual fixed or operable panel that meets all of the following conditions shall be considered to be a
hazardous location:
1. The exposed area of an individual pane is larger than 9 square feet (0.836 m2),
2. The bottom edge of the glazing is less than 18 inches (457 mm) above the floor,
3. The top edge of the glazing is more than 36 inches (914 mm) above the floor; and
4. One or more walking surfaces are within 36 inches (914 mm), measured horizontally and in a straight line, of the
glazing.
