Negative information includes bad payment history or court records (judgements & notices).
this information should be used to assess the prospective tenant's payment history.
Ultimately it is up to the landlord to decide whether to take on a tenant or not - different landlords may have different appetites for risk, meaning that one landlord may take on a tenant that another would decline, and vice versa.
Where there is a negative history from a four or five years ago, the agent or landlord can consider that as less risky than an applicant with a consistent history of negative payment or where there is a recent negative record - where the concern is that the applicant may have gotten him/herself into financial trouble and more negative information could soon follow.
The other points to consider when interpreting negative data is the date of the information, how many negative records vs positive records there are, and the Rand amount of the negative information.