What is a delimiter?

The idea in one line

Computers store a list of values as one long run of characters. A delimiter is the agreed-upon marker that says "a new value starts here." Without it, JohnDoe42 is meaningless; with commas, John,Doe,42 is clearly three fields: first name, last name, age.

The common delimiters

Delimiter	Name	Where you see it
,	Comma	CSV files, spreadsheet exports, lists of tags.
tab	Tab (TSV)	Data copied out of spreadsheets, database dumps, log files.
;	Semicolon	CSV in locales where the comma is the decimal separator (much of Europe).
|	Pipe	Log formats and data feeds, because pipes rarely appear inside the data itself.
newline	Line break	One item per line - the simplest delimiter of all.

Delimited formats: CSV and TSV

The two formats you meet most are CSV (comma-separated values) and TSV (tab-separated values). Both are just plain text where rows are separated by line breaks and fields within a row are separated by the delimiter. They are popular because almost everything can read and write them: spreadsheets, databases, scripts, and text editors.

The catch is that "comma-separated" is a convention, not a strict standard. Different tools disagree about quoting, escaping, and whether the first row is a header. That is why the same CSV can look perfect in one app and scrambled in another.

The edge case that breaks everything

What happens when the delimiter appears inside a value? Consider a name field containing Doe, John in a comma-delimited file. A naive split would turn one field into two. The usual fix is to wrap fields in quotes: "Doe, John",42. Now the comma inside the quotes is data, and only the comma outside is a delimiter.

This is the single most common reason CSV imports go wrong. If a file misbehaves, check whether a value contains the delimiter, and whether the exporter quoted it.

Choosing a good delimiter

• Pick a character that will not appear in your data. Pipes and tabs are popular precisely because they are rare in normal text.
• Be consistent - one delimiter for the whole file.
• If you must use a common character like a comma, make sure your tool quotes fields that contain it.
• For one item per line, the line break is the cleanest delimiter and needs no quoting at all.

Splitting and reordering delimited text

Once you know the delimiter, you can split a run of text back into its individual values to sort, dedupe, or reorder them. In TextLab, Custom mode in Arrange Mode lets you type any delimiter - comma, tab, semicolon, or your own string - split the text on it, drag the values into a new order, then rejoin them with the same delimiter. Handy for reordering a list of tags or cleaning up a pasted CSV row on a phone.