Layout theme elements (FileMaker Pro Advanced)
Every theme file must begin with an XML-document processing instruction that declares it as an XML document using the XML 1.0 specification. In addition, an XML document for a layout theme must contain the <FMTHEMES> and </FMTHEMES> start and end tags for the file. This FMTHEMES root element can contain one or more FMTHEME elements.
The following are the minimum elements required for a theme file:
<?xml version="1.0" standalone="yes" ?>
<FMTHEMES>
<FMTHEME>
<THEMENAME VALUE="Blue and Lemon Screen" />
</FMTHEME>
</FMTHEMES>
Containing all of your themes (FMTHEME elements) in one file is useful if you want to organize the way that themes appear in the New Layout/Report assistant. The order that FMTHEME elements are listed in the file determines the order in which the THEMENAME values appear.
Note  Values for the THEMENAME element can contain any characters from the ASCII character set. However, if you’re using an XML editor to write your themes or if you plan to use the themes on different platforms, certain measures must be taken.
XML editors expect these characters to be coded as character entities:
 
Using the character instead of the character entity results in an error from the XML editor. However, FileMaker Pro and FileMaker Pro Advanced do not reinterpret character entities. Values in the THEMENAME element will appear exactly as typed. You can avoid the problem by using a text editor to create your themes or by ignoring the error from the XML editor. Your theme names will appear as you write them in the New Layout/Report assistant.
XML elements for layout parts
An FMTHEME element can contain any of the following multi-line elements to describe the parts in a layout. Each layout part element contains additional elements to describe the background fill, text, field labels, and fields in the layout part.
Elements for layout parts can be listed in any order within an FMTHEME element in the XML document. However, if two identical elements are listed (such as two BODYPART elements), FileMaker Pro Advanced will only use the attributes for the last one in the list.
 
This multi-lined
element is used
Title header — appears only once at the top of the first screen or page.
Header — appears at the top of every screen or page, except the first one if there’s a title header.
Leading grand summary — appears at the beginning of a report and displays a summary field for all the records in a found set. A layout can have only one leading grand summary part.
Leading subsummary — appears above the body part and displays a summary field for a subset of records as defined by the break field. You can describe up to nine leading subsummary layout parts. Each LEADSUBSUMPART element must contain a PARTNUMBER element to distinguish it from the others.
Body — appears in the middle of every screen or page. A layout can have only one body part.
Trailing subsummary — appears below the body part and displays a summary field for a subset of records as defined by the break field. You can describe up to nine trailing subsummary layout parts. Each TRAILSUBSUMPART element must contain a PARTNUMBER element to distinguish it from the others.
Trailing grand summary — appears at the end of a report and displays a summary field for all the records in a found set. A layout can have only one trailing grand summary part.
Footer — appears at the bottom of every screen or page, except the first one if there’s a title footer.
Title footer — appears only once at the bottom of the first screen or page.
Notes
  •
Although a theme may include descriptions for every type of layout part, the type of layout you select in the New Layout/Report assistant determines which parts will appear in your new layout or report.
  •
Any layout part element can contain FIELD, TEXTLABEL, and TEXT elements that are used to describe the characteristics of text or data in the part.
The FIELD element is used to describe text (data) in fields and field borders. The TEXTLABEL element is used for field label text. Field labels are displayed in the body part of a layout or in other parts such as the header of columnar reports. The TEXT element describes all other text that appears in a layout part, such as title text in the header.
Related topics 
Creating custom layout themes (FileMaker Pro Advanced)
Removing elements from theme files (FileMaker Pro Advanced)
Layout theme attributes (FileMaker Pro Advanced)
Specifying default values for themes (FileMaker Pro Advanced)
Using values for patterns and colors (FileMaker Pro Advanced)
Troubleshooting custom layout themes (FileMaker Pro Advanced)