12.6.13 Embedded-text Flow Object Class
The embedded-text flow object class is used for embedding right-to-left text within left-to-right text or vice-versa. This flow object class shall only be inlined.  It has a single principal port.
An embedded text flow object has the following characteristics:

•  direction: is one of the symbols left-to-right or right-to-left. It shall be parallel to the writing-mode of the paragraph. This characteristic is not inherited and shall be specified.

•  language: is #f or a symbol specifying the ISO 639 language code in upper-case. This affects line composition in a system-dependent way. The initial value is #f.

•  country: is #f or a symbol specifying the ISO 3166 country code in upper-case. This affects line composition in a system-dependent way. The initial value is #f.

•  inhibit-line-breaks?: is a boolean specifying whether line breaks shall be inhibited before and after each area produced by this flow object. This applies only to line breaks introduced by the formatter to make lines fit in the available space. The initial value is #f.
The effect of the embedded text flow object is to make any line fragments that contain the content of the embedded text flow object use the specified direction as their inline-progression direction. For example, suppose a line contains four inline areas whose order (in the flow object stream) is A, B, C, D, where the B and C were contained in an embedded text flow object whose direction was the reverse of the paragraph's writing-mode.  Then the line shall be built up as follows: first a partial line shall be built up containing B and C by placing the position point of C on the escapement point of B.  Then the resulting partial line area shall be treated as an inline area whose position point is the escapement point of C and whose escapement point is the position point of B.  The line shall then consist of A, then the inline partial line area produced from B and C, and finally D all placed using the writing-mode of the paragraph. See Figure 12, Mixed Writing-Mode for Hebrew and English.