Extrude's start_offset says which way it goes: along the sketch normal, also with direction: negative (where a positive offset starts on the far side of the sketch from the extrusion)

The params doc listed start_offset? with no description, and an extrude in direction negative with a positive start offset surprised a user. The behaviour is unchanged (an offset start plane, as in Fusion); the params doc of solid.extrude and the Extent field doc say so.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/doc/src/document.rs

@@ -125,7 +125,8 @@ pub struct Extent {
     /// Optional second side distance (two-sided extrude), along the negative normal.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub distance2: Option<String>,
-    /// Start offset from the sketch plane (expression).
+    /// Start offset from the sketch plane (expression), along the sketch normal whatever the
+    /// direction.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub start_offset: Option<String>,
     /// Through all bodies in the direction(s) instead of `distance`.