How to read the band →
Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Cecilia
Cecilia has been climbing in recent years. All-time it's been given to 111,688 U.S. babies, the 355th most common name by sound today, peaking at 2,506 in 2025, with 2,506 in 2025.
Cecilia has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).