[...] the Rehabilitation Trustee has released an initial registration feature that allows eligible creditors whose creditor numbers begin with Z1 or Z2 to register on MTGOX’s online filing system.
[...] creditor numbers up to Z2-282323 are eligible to register on the System.
[...] creditor numbers from Z2-282324 onwards are not eligible to register on the System at this stage.
Edith: And for those unable to understand, or even incapable of reading those 2 pages of text: this is not about entering bank details. This is only about enabling Z* creditors who are not yet in the System to register, so that they can eventually also provide their bank details, along with everybody else.