3 Specify lowercase or uppercase for units.
13 `string`: `"lower"|"upper"`
17 The following patterns are considered violations:
45 width: calc(10PX * 2);
49 The following patterns are *not* considered violations:
59 width: calc(10px * 2);
65 The following patterns are considered violations:
93 width: calc(10px * 2);
97 The following patterns are *not* considered violations:
107 width: calc(10PX * 2);