Intimation          regarding subsequent changes in constitution, etc.
23. If          after the date of the application, or of the last application where more          than one application are made, for registration of a firm for any          assessment year and before the assessment for that assessment year is          completed by the [Assessing Officer], so far as known to the firm, any          change or changes take place in the constitution of the firm or the          shares of the partners, the details of such change or changes shall be          communicated by the firm to the [Assessing Officer] as soon as possible          after each such change takes place.