diff --git a/silverbullet-query/SKILL.md b/silverbullet-query/SKILL.md
index b3bb485..4bff2a4 100644
--- a/silverbullet-query/SKILL.md
+++ b/silverbullet-query/SKILL.md
@@ -45,6 +45,9 @@ where p.name:startsWith("proj/")
 -- Pages with a specific tag
 where table.includes(p.tags, "account")
 
+-- Pages WITHOUT a specific tag
+where not table.includes(p.tags, "account")
+
 -- Pages matching name
 where p.name:startsWith("Person")
 
@@ -55,6 +58,8 @@ where t.page == _CTX.currentPage.name
 where p.name:startsWith("proj/") and table.includes(p.tags, "active")
 ```
 
+> **Important:** `p.tags` is always an array (possibly empty) on every page. Do NOT use `p.tags` or `not p.tags` as a boolean check — an empty array is still truthy in Lua, so `not p.tags` is always false. Always use `table.includes()` to check for specific tags.
+
 ### Sorting (`order by`)
 
 ```