in layman's language:

even though the employment tribunal rules of procedure require that the address of the claimant must be included on claim forms submitted to tribunals, that is merely a procedural rule and failure to comply with it will not automatically mean the claim must be rejected. In this case a claimant was represented by solicitors whose address was provided on the form although her own was not. The EAT held that in all the circumstances it would be appropriate that the claim should be accepted for hearing in spite of this technical breach of the requirements of the rules of procedure.

in legal language:

• where a claimant fails to complete form ET1 by omitting "relevant required information" (in this case by not including her address), the question of what is "relevant" or "irrelevant" must be viewed in the context of the particular claim form and, further, the question to be asked is whether the failure in question is "material" or "immaterial" in the context of the particular claim and the requirements of the Rules of Procedure.
  
• where a Chairman's decision on the applicability of the Rules of Procedure is challenged on the basis of an error of law, the correct procedure is to appeal to the EAT. To seek a review of such a decision is inappropriate.

For relevant general notes see Employment tribunals/overriding objective and/or Procedure of Employment Tribunals/appeals and review/review of tribunal decision .