formatting - Can I make the subsection CounterBox continue counting across section boundaries?

This is what I used in a stylesheet for Section

CellDingbat->Cell[TextData[{CounterBox["Section"], "."}]]

This is what I used in a stylesheet for Subsection

CellDingbat->Cell[TextData[{CounterBox["Subsection"], "."}]]

As you can see, the subsection counter get reset when I start a new section. How can I get the subsection counter to continue its count in the new section.

Answer

The thing which resets the "Subsection" counter is the CounterAssignments option. The option includes a list of assignments, including:

{"Subsection", 0}

which just means that, beginning in that cell, the "Subsection" counter is assigned to 0 (and will be incremented to 1 beginning at the next cell).

You can use the Option Inspector to change the option on a specific Section cell, or you can change the stylesheet for the entire notebook. To change the stylesheet, choose the Format->Edit Stylesheet... menu item, then paste and interpret the following cell expression at the end of the stylesheet:

Cell[StyleData["Section"], CounterAssignments->

    {{"Subsubsection", 0}, {"Item", 0}, {"Subitem", 0}, {"Subsubitem", 0},
     {"ItemNumbered", 0}, {"SubitemNumbered", 0}, {"SubsubitemNumbered", 0}}]

This just mimics the default list for the Section style, but omitting the "Subsection" counter setting.