Microsoft Office SharePoint Server 2007 (MOSS) has two content type groups defined for publishing pages:
1. Page Layout Content Types
2. Publishing Content Types
Figure 1: Publishing Content Types in MOSS
All content types in “Page Layout Content Types” group derive (inherit) from “Page” content type.
Both SharePoint Designer (SPD) and browser interface of MOSS wouldn’t let you associate a content type to a page layout unless the content type drove from base “Page” content type, but be careful when using SharePoint upload technology with master page gallery; make sure that associated content type is “Page” or one of its derived content types.
Figure 2: Associated Content Type for Page Layout must point to Page content type or one of its derived content types
If you are new to MOSS publishing architecture, it may seem more logical at a first sight to pick “Page Layout” as an associated content type for a page layout, but that would be wrong.
Out of the box (OOTB) “Page Layout” content type column is missing many key field controls that are part of core MOSS publishing architecture.
Figure 3: OOTB “Page” Content Type
Figure 4: OOTB “Page Layout” Content Type
Notice that the “Page Layout” content type is missing scheduling columns and target audience column.
Therefore you should always use “Page” content type or one of its derived content types as an associated content type when uploading page layouts to a master page gallery.
HTH,
Talha