Example filename: USA_PET_PUPPY_2026_A.jpg · Positions are 1-based characters of the original filename (excluding extension).

Feature	Prefill (you type)	Auto-fill (next rows)	Result in Preview	Notes
Simple letter sequence	X, Y	Z, A, B …	…_X, …_Y, …_Z	Wraps A→Z continuously
Alphanumeric with leading zero	A3B05, A3B07	A3B09, A3B11 …	USA_A3B05.jpg …	Numeric part increments; leading zero preserved when present
Repeating pair pattern	A, A, C, C	E, E, G, G …	…_A, …_A, …_C, …_C	Write the repeat block twice so Smart Fill skips ahead correctly
Fixed-suffix repeat pattern	DOF, DOK	DOF, DOK …	…_DOF, …_DOK	Alternates indefinitely; tip — include the suffix (e.g. `5_, 6_, 7_`) to lock it
Position list (char extract)	[5,6,7,3-1]	same for all rows	PETASU	Chars at pos 5,6,7 = PET; pos 3 down to 1 = ASU (from USA_PET_PUPPY_2026_A)
RegExp extract	/\d+\//	same for all rows	2026	Extracts the first run of digits — yields 2026 from the filename
RegExp — full name slice	/[1-50]\//	same for all rows	USA_PET_PUPPY_2026_A	Advance mode: grabs chars 1–50 of the original name (without extension)
Move to new subfolder	USA_PET_PUPPY_2026_A/	combine with other cols	USA_PET_PUPPY_2026_A/ …renamed….jpg	Trailing `/` creates a subfolder named after the value and moves the file into it