PIC (18 series) 12-bit Instruction Addressing?
The d and a bits are fields in the instruction encoding, but not part of the 8­-bit address field in the instruction. If we want to be academic about it, we could say that the a bit is an addressing mode field in the instruction. The d bit can be analyzed as a destination addressing mode or as part of the opcode, but the 00 you start by quoting are not part of addressing at all; they are simply the last two bits of the MOVF opcode.

The 12-bit effective address used is constructed as the 8 address bits from the instruction, prepended by 4 bits that either come from the BSR or are derived from the first few of the explicit address bits, as selected by the a field. But the value of the a bit itself doesn't become part of the address.

Finally (but I may be misreading the documentation I could find here), the ,A in the assembler syntax seems to stand for "use the Access bank", so when (upper-case) A is present in the assembler instruction, it means that (lower-case) a in the binary instruction encoding is zero and the BSR is not used.