To use a paragraph format to force a jump from contents or index to a secondary window, assign property Window to the format of the paragraph that is the target of the contents or index entry (not to the paragraph format of the entry itself):
[HTMLParaStyles] ; Window specifies only that access from the contents or index ; opens the topic in the window named in [StyleWindow] TopicHeadingFmt=Window
Also assign the name of the secondary window to the target paragraph format:
[StyleWindow] ; para style = window to use in HH when accessed from contents ; or index TopicHeadingFmt=wndwname
A jump from the contents loads a topic in a secondary window only if the first paragraph in the topic has a format assigned the Window property. However, a Window PI marker in the first paragraph overrides any Window property assigned to that paragraph format.
A jump from the index loads the topic in a secondary window if the Window paragraph format appears anywhere in the topic. For paragraphs after the first in a topic, whichever comes first, Window PI marker or paragraph assigned the Window property, determines which secondary window will be used for jumps from the index.