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Dim sTab As String
sTab = "Planning_Zones"
Print sTab + ", table format: " + IIf(TableInfo(sTab, TAB_INFO_DATA_FORMAT)=5, "Native", IIf(TableInfo(sTab, TAB_INFO_DATA_FORMAT)=14, "NativeX", "Other"))
A few methods have been discussed and there's also a clue in the TAB file itself if you open it as a text file.
Type NATIVE Charset "WindowsLatin1"
Type NATIVEX Charset "WindowsLatin1" Locale "en-GB"
I would imagine, however, than none of these methods are helpful in managing a mixture of TAB and TAB Extended file sets. My only suggestion is to use folder names (or file names) to determine whether it's a TAB or TABX, so that users with 32-bit Pro, or other software that cannot handle TABX yet, can know there's no point in even trying to open it!