make it possible for symbol/value="" to pass validation -- the empty strings in f[@name eq 'msd']/symbol are a regular "feature" of the morphosyntactic description in this sample
Change-Id: I6bf77a4c3344d93e8abdd8df32732ecf94a6dd9b
diff --git a/nkjp2korap_sample1/NKJP_morphosyntax.rng b/nkjp2korap_sample1/NKJP_morphosyntax.rng
index 845035d..4a7857e 100644
--- a/nkjp2korap_sample1/NKJP_morphosyntax.rng
+++ b/nkjp2korap_sample1/NKJP_morphosyntax.rng
@@ -8205,9 +8205,11 @@
<rng:attribute name="value">
<a:documentation xmlns:a="http://relaxng.org/ns/compatibility/annotations/1.0">supplies the symbolic value for the feature, one of a finite list that
may be specified in a feature declaration.</a:documentation>
- <data type="token">
- <param name="pattern">(\p{L}|\p{N}|\p{P}|\p{S})+</param>
- </data>
+ <optional>
+ <data type="token">
+ <param name="pattern">(\p{L}|\p{N}|\p{P}|\p{S})+</param>
+ </data>
+ </optional>
</rng:attribute>
<ref name="att.global.attributes"/>
<empty/>