This should be obvious, but it seems it's not. Extend the paragraph
which introduces conn= specs for USB devices. Mention that colons are
not available within conn= specs because they are used to separate -d
fields from each other (driver name, and options like 'conn').
.RB " $ " "sigrok\-cli \-\-driver=ols:conn=/dev/ttyACM0" " [...]"
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Some USB devices don't use a unique VendorID/ProductID combination, and thus
-need that specified as well. This also uses the \fBconn\fP option, using
-either \fBVendorID.ProductID\fP or \fBbus.address\fP:
+need that specified as well. Notice that colons are used to separate the
+driver name from the \fBconn\fP option, thus colons cannot be used within the
+\fBconn\fP option's argument. To select a specific USB device, use either
+\fBVendorID.ProductID\fP or \fBbus.address\fP:
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USB \fBVendorID.ProductID\fP example:
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