<xsd:documentation>An empty string is the default representation of a null value for a
curve (i.e. when the null value representation is not explicitly defined).
If a null value is defined in the logCurveInfo, it overrides any null value specified at the
logHeader level. An empty string is always a valid null value representation in the comma delimited list.
An empty string is not a valid null value representation within a space delimited array.
Specifying a null value also makes it easier to transform data back to a
legacy format without having to scan the data to insure that the null pattern
does not exist in the data. </xsd:documentation>
<xsd:documentation>True (true or 1) if this curve is a candidate to be a primary index.
False (false or 0) or not given, indicates otherwise.
An index curve should monotonically change when sorted on its own values (i.e., no duplicates). </xsd:documentation>
<xsd:documentation>Offset of sensor from drill bit.
This element is only informative. The measured depth values
are at the actual depth (not bit depth from which you must
subtract the offset).</xsd:documentation>