The Service Level Agreement (SLA) is an efficient and proven tool for regulation of the relations between the supplier and the user of services that is designed to ensure their quality. Such agreements are well known and successfully used in the information and communication industry. They are also applicable in other areas. Essentially, SLA stipulates certain requirements for the service level of which the fulfilment is guaranteed by the provider. In case of SLA violation the service provider is usually financially liable. As a rule, in such cases the user is remunerated with a discount for services provided in the following accounting period. Dependability requirements are an important part of the SLA. The purpose of this paper is to familiarize a wide range of experts from various industries with the general matters of SLA application and the aspects related to the dependability requirements specification. The paper refers to the relevant documents of international standardization organizations (ITU, ISO/IEC, ETSI, TMForum) and the Russian standards. Recommendations are given for selecting the dependability indicators and standard values to be included in the SLA, as well as for defining the amounts of compensation payed by service providers to the customers in case of non-compliance with requirements for the availability factor. The availability factor is normally used in the SLA as the primary dependability indicator that defines the allowable total time of non-operability over the specified base period. Additionally, a client might be interested in restricting the duration of each individual downtime as well. For that purpose, the guaranteed recovery time can also be specified and exceeding this time would be deemed an SLA violation. The choice of the standard values for inclusion in the SLA is a search for a compromise between the intent to satisfy the user requirements and the wish to get ahead of the competition on the one hand and the requirement to ensure the feasibility of the assumed obligations and minimize the risk of SLA violation that involve financial and reputational losses on the other hand. Therefore, before proposing an SLA to a customer, a service provider must thoroughly analyze its actual ability to make sure that the probability of SLA requirements violation is sufficiently low. The computational or computational and experimental methods are suggested for its evaluation. The amount of compensation for a violation depends on its gravity, i.e. the achieved and the standard values of an indicator. In practice, this relation is usually expressed with a step (piecewise constant) function. A formula is proposed that expresses the theoretical relation between the relative amount of compensation for violation of the availability factor requirements and the severity of violation and the standard value of this indicator. It can be used in defining the technically substantiated reference for SLA conditions development and assessment, of which the value will be relevant to both the service providers and users.