Each type of innovative financing instrument is examined in turn, starting with a short description of the instrument, an evaluation of its current use in the water and sanitation sector and an evaluation of the role that ODA can play in developing the use of such instruments. The list that appears in this table is clearly not exhaustive, as there is almost unlimited potential for innovation in this area. Besides, such innovations are often combined as financial structures need to be tailored so as to adapt to the critical mismatches that materialise in each case. Table 3.3 at the end of the section evaluates the applicability of these financial mechanisms to different sets of circumstances. The main purpose of blending is to use grants so as to allow attracting repayable financing that would not have been provided otherwise, whilst ensuring that the resulting project is not so expensive that the poor are excluded from the service. For example, ODA grants can be provided as interest rate subsidies (Section 3.2), seed financing for revolving funds (Sections 3.2 and 3.5), contributions to the establishment of project preparation facilities (Section 3.9), etc.