Such a close tie to the structure of a specific user agent format can make the process of setting capability properties very sensitive, causing even minor changes to the user agent to negatively affect the process.
This is exactly what happened with Internet Explorer Mobile on Windows Mobile 6 and Windows Mobile 6.1.
For a Windows Mobile 5.0 Pocket PC, there are three browser entries in the pie.browser file that collectively define the Internet Explorer Mobile capability properties. Notice that in addition to providing a match for the user agent value, the regular expression in the section stores five variable values which are used to set the capability properties as shown in table 1. Internet Explorer Mobile capabilities defined by Win CE browser section for Windows Mobile 5.0 As you can see, the capability definitions for Internet Explorer Mobile are tied very closely to the contents and structure of the user agent string; this is true for most browsers.
The WM6Plus.browser file contains two browser sections and three gateway sections.
The first browser section, IEMobile, handles setting the majority of Windows Mobile 6 and Windows Mobile 6.1 Internet Explorer Mobile capabilities.
Now , based on sourced information from Taiwanese handset makers, is reporting a "touch interface" version of Windows Mobile 6.5 set for release in February 2010 -- an upgrade to the initial Windows Mobile 6.5 launch expected on October 1st.
However, instead of phasing out Windows Mobile 6.5 with the Q4 2010 launch of Windows Mobile 7, asserts that Microsoft will lower the price of Win Mo 6.5 to compete against open-source Android devices while positioning Win Mo 7 to go head-to-head with the i Phone.