From the Autodesk help menu;
Baseline Point. This is a point on the assembly typically representing the start point of the first subassembly that is attached to the assembly near the controlling alignment. By default, the baseline point coincides with the insertion point and therefore follows the centerline alignment and profile. If you want to begin sectional elements oriented away (horizontally and vertically) from the centerline, do so by moving this baseline point away from the assembly insertion point.
Why is this the extent of Baseline Point HELP information on assemblies? As it is I have to edit the baseline point, apply it to my corridor, see the result, if NOT what I wanted I have to edit it again, apply it, select the corridor, change the assembly to something else, apply then go back in and change the assembly back to my edited baseline assembly I wanted to see in the first place because rebuild corridor will not apply edited baseline assemblies at first. There is zero information I can find on Baseline Point within assemblies.
What I'm after is changing the UrbanCurbGutterGeneral subassembly from Flange code to Flowline_Gutter code. In reality I have to get it correct the first time I try or it's a battle to change it down the line. I once found some good information on Baseline Point, but that link is now dead.
