Member record meta-validity documentation.

MODULES.md

@@ -150,6 +150,52 @@ Sets the value of given ```key``` in dictionary stored as section
 ```sec``` in given ```mr``` structure to the new ```value``` if and
 only if it is not already present.
 
+    (member-source mr)
+
+* ```mr``` - a member record structure
+
+Returns a list of strings representing the source file of this member
+record.
+
+    (member-record-info mr key [default])
+
+* ```mr``` - a member record structure
+* ```key``` - key (symbol) to retrieve
+* ```default``` - optional default value
+
+Like ```dict-ref``` returns the value associated with ```key``` in
+section ```'info```. If ```default``` is provided, it is passed on to
+the underlying ```dict-ref```.
+
+    (member-missing-keys mr)
+
+* ```mr``` - a member record structure
+
+Returns a list of keys (symbols) from within the ```'info``` section
+of given ```mr``` that have ```#f``` values (indicating they are
+missing mandatory fields in the source).
+
+    (member-has-highlights? mr)
+
+* ```mr``` - a member record structure
+
+Returns ```#t``` if given ```mr``` has at least one source highlight.
+
+    (member-record-usable? mr)
+
+* ```mr``` - a member record structure
+
+Returns ```#t``` if it is possible to work with this member - mainly
+that the ```'info``` section contains the ```'member``` key.
+
+    (member-has-problems? mr)
+
+* ```mr``` - a member record structure
+
+Returns ```#t``` if there are any ```'error``` type highlights in
+```mr```, or it is not ```member-record-usable?``` or the
+```member-id``` is not 4-digit prime number.
+
 ### Member Parser
 
 ### Members Directory