+/*
+ * A valid entry name uses characters from the "portable character set"
+ * (more commonly referred to as US-ASCII), and disallows some of the
+ * punctuation characters:
+ *
+ * '/' is a pathname separator
+ * '\' may be a pathname separator, but more important, is an escape
+ * '|' delimits names and description
+ * '#' denotes a numeric value
+ * '=' denotes a string value
+ * '@' denotes a cancelled symbol
+ * ',' separates terminfo capabilities
+ * ':' separates termcap capabilities
+ *
+ * Termcap capability names may begin with a '#' or '@' (since they have
+ * exactly two characters).
+ */