Crystallographic orientations of the Y211 tracks that were trapped within the melt-textured Y123 domains were determined from the orientation relationship among the Y211 pattern, [110] twin traces and a microcrack. Analysing the orientation of the two-dimensional Y211 patterns that were observed on various crystallographic planes of the Y123, the three-dimensional shape of the Y211 pattern was inferred as follows : only one x-type Y211 pattern was included within one Y123 domain and three sets of diagonal Y211 tracks met with the corners of the Y123 domain. The diagonal Y211 tracks lie on the (110), (<(1)over bar 10>), (011), (0(1) over bar1$), (101) and (10(1) over bar) planes of the Y123 domain. The planes where the Y211 tracks are located are considered to be the boundary planes where local growing parts of the Y123 domain impinge upon each other. The formation mechanism of the Y211 pattern is discussed on the basis of anisotropic growth behaviour and the shape of the Y123 domain.