Lower letters

Location on ribbon: Tab DVD Addin → Group Text and Number

Command ID: btnLowerLettersSerial

What it does

Fills the selected cells with a lowercase letter sequence a, b, c, … in the order the selection is walked. After z the sequence continues with aa, ab, ac, …, so it is not capped at 26 rows the way a manual drag often is.

In construction paperwork, lowercase letters are the usual third numbering level: below Roman headings (I, II, III) and numeric headings (1, 2, 3) sit the detail items a, b, c — pavement layers, component details under one work item, or sub-clauses in an acceptance record.

How to use

1. Select the cells that need a sequence — a column, a row, or a multi-cell block.
2. Go to the DVD Addin tab → Text and Number group → click Lower letters.
3. The add-in walks the selection left to right then down, skips any cell in a hidden row or column, and counts each merged area once (writing into its top-left cell).
4. Values are written straight into the cells. Excel's status bar shows Filled N cells. for about 8 seconds.

If every cell in the selection is hidden or a duplicate of an already-counted merge, the add-in reports No usable cells (all hidden or duplicate merges). and writes nothing.

Example

A pavement structure quantity table, numbering the detail layers under the "Road pavement" work item:

Before	After
(empty) — Fine-graded asphalt concrete, 5 cm	a — Fine-graded asphalt concrete, 5 cm
(empty) — Coarse-graded asphalt concrete, 7 cm	b — Coarse-graded asphalt concrete, 7 cm
(empty) — Graded crushed stone type I, 15 cm	c — Graded crushed stone type I, 15 cm
(empty) — Graded crushed stone type II, 30 cm	d — Graded crushed stone type II, 30 cm

Select the four cells in the No. column, click Lower letters, and the column is filled — no typing, no fill handle.

Notes

• The command overwrites whatever is in each selected cell, formulas included, so make sure the numbering column is what you have selected.
• Ctrl+Z will not undo it: the add-in writes to cells directly, so Excel records no undo step.
• Hidden rows and columns are skipped entirely; the letter sequence stays unbroken across the visible rows.
• Each merged area receives a single letter, placed in its top-left cell.
• With nothing selected, the status bar shows Please select a data range. and the command stops.

Related

• Upper letters — same mechanism, filling A, B, C, … for a higher numbering level.
• Roman numerals — fills I, II, III, … for the major sections of a document.
• Numbering — fills a numeric series with a chosen start value and step.
• Lower letters list — prefixes existing text with a., b., c. instead of overwriting it.