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).
Diego
Diego is down from its peak but still widely used. All-time it's been given to 126,405 U.S. babies, the 285th most common name by sound today, peaking at 8,423 in 2006, with 2,356 in 2025.
Diego has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).