diff --git a/src/dm/tools/sheet.md b/src/dm/tools/sheet.md
index da943ab..e9955b3 100644
--- a/src/dm/tools/sheet.md
+++ b/src/dm/tools/sheet.md
@@ -1,6 +1,6 @@
 Write a character's mechanical state: create the character, or patch the sheet.
 
-Give `character`, the slug that names the character's directory under `characters/`, like `sister-maren`.
+Give `character`, the slug that names the character's directory under `characters/`, like `sister-maren`. The slug is the character's own name, lowercased and hyphenated, and it is permanent: the record, the logs, and every wikilink will carry it. Never use a placeholder like `your-bard` or `new-character`. A character without a name is not ready for a sheet, so ask the player for the name, or offer a few fitting ones, before you create.
 
 Give `sheet`, the frontmatter keys to write. Every value is absolute, never a change: after a seven-point wound, write `hp: 15`, never `-7`. Absolute values keep a misremembered subtraction from compounding. On a character who already exists, the keys you name are the keys that change; every other key keeps its value and the prose stays as it is. You decide what keys a character needs. The only key the engine reads is `name`, the name the transcript shows.