There's no general public info on a certain "hdb responses sort 1k 28" as this is simply not a regular HDB identifier. Even so, HDB gives a number of channels for suggestions. The main process is from the "Publish to Us" e-comments form around the HDB website. This way means https://hdborcondo901766307.bleepblogs.com/37572011/hdb-feedback-form-1k-28