I am the assigned ART-ART reviewer for this draft.

Summary:

  This draft is clear and easy to read, and the overall approach of signaling domain availability via a reserved underscored DNS leaf node fits well with existing DNS usage patterns. From an ARTART perspective, the document is generally in good shape. A small number of clarifications would further improve implementability at the application layer and reduce the risk of divergent interpretations.

Major issues:

  None.

Minor issues:

  Section 3.2 discusses the handling of TXT RDATA containing UTF-8 text, including the representation of Internationalized Domain Names (IDNs) as either A-labels or U-labels. While the intent is understandable, it is not entirely clear whether U-labels are intended only for textual or documentary representation, or whether applications are expected to process them directly.

  A brief clarification of the expected roles of A-labels versus U-labels, particularly with respect to operational DNS resolution versus presentation or informational use, would be helpful. For example, a short statement indicating that DNS resolution relies on A-labels while U-labels are intended for presentation would remove potential ambiguity for application developers.

  Additionally, the document states that UTF-8 data may be encoded using "octal escapes". In the DNS context defined by RFC 1035, the \DDD escape form represents decimal-encoded octet values rather than octal values. Using the term "octal escapes" here may be misleading and could result in incorrect implementations. Consider rephrasing this to explicitly refer to decimal numeric escape sequences or to RFC 1035 character-string encoding.

Nits:

  None.

Additional Note:

  As a purely optional and non-blocking observation, and speaking from a Japanese language perspective: in the example in Section 3.2,

      _for-sale IN TXT "v=FORSALE1;ftxt=\229\163\178\229\135\186"

  the UTF-8 encoded text decodes to the string "売出". While this form is understandable, when expressing a state in Japanese it is more common to use the form "売出中" (meaning "now for sale") rather than "売出" alone, although it would increase the encoded length to nine octets (\229\163\178\229\135\186\228\184\173). This comment is offered only as a linguistic note and does not require any change to the document.