The description of the infoWindow option is: "T*he InfoWindow in which to render text information when a marker is clicked. Existing info window content will be overwritten and its position moved. If no info window is specified, the DirectionsRenderer will create and use its own info window. This property will be ignored if suppressInfoWindows is set to true"*
So you can not provide window text to be displayed when the lettered markers are clicked, you need to suppress the marker and supply your own markers and windows. I use the google chart icons http://code.google.com/apis/chart/image/docs/gallery/dynamic_icons.html to create lettered/numbered icons. If you specify suppressInfoWindows: false you will still be able to click on the individual intermediate directions steps and have the window popup to show the location of the step while if you specify true you would not have access to the intermediate windows. -- You received this message because you are subscribed to the Google Groups "Google Maps JavaScript API v3" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-maps-js-api-v3/-/v4AU5Y0hUU4J. To post to this group, send email to google-maps-js-api-v3@googlegroups.com. To unsubscribe from this group, send email to google-maps-js-api-v3+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-maps-js-api-v3?hl=en.