TBL-004 Cell pattern

Overview

Validates that the cell values in a specific column match the regular expression given by pattern. Non-matching values trigger an error.

Why it matters

When an ID column follows a fixed format like REQ-001, enforcing the format with pattern prevents notation drift (req001, REQ_001, #REQ-001, etc.). This is the right tool when expressing the format itself as a regex scales better than enumerating allowed values.

Options

Field	Type	Required	Description
column	string	Yes	Column name to validate
pattern	string	Yes	Regular expression (JavaScript RegExp syntax; validated at config load time)
files	string	—	Glob of files this rule applies to

Bad example

| ID         | Description       |
| ---------- | ----------------- |
| REQ-001    | User registration |
| req-002    | Password reset    |

With column: "ID", pattern: "^REQ-\\d{3}$", the lowercase req-002 triggers a violation.

docs/requirements.md
  line 4  error  Value "req-002" in column "ID" does not match pattern "^REQ-\d{3}$"  TBL-004

After fix

| ID         | Description       |
| ---------- | ----------------- |
| REQ-001    | User registration |
| REQ-002    | Password reset    |

Configuration example

{
  "rule": "tbl004",
  "options": {
    "column": "ID",
    "pattern": "^REQ-\\d{3}$"
  }
}

In JSON, backslashes must be escaped, so \d is written as \\d.

Related rules

• TBL-003 Allowed values — Constrain values by list (simpler than a pattern)
• TBL-005 Cross-column constraints — Constrain relationships between columns