RFC 004

RFC-4 -- Block sequence entries must use space after dash

Tests: ...

YAML allows a TAB character to come after the '-' dash starting a block sequence entry. There is no good reason to allow this.

The YAML Spec 1.2 says that the dash must be followed by a non ns-char. That includes tab #x9, space #x20, newline #xA and carriage return #xD.

Allowing the tab is confusing and probably an oversight. We should tighten the spec to not allow it.

1.3 Rationale

Probably nobody is aware that this allowed and nobody is using it. Let's tighten this down ASAP.