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).
Harold
Harold is now well below its former popularity. All-time it's been given to 554,280 U.S. babies, the 1,587th most common name by sound today, peaking at 14,230 in 1924, with 230 in 2025.
Harold has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).