Inthe encodingsystemof 16bit widthsuch asUTF-16 of Unicode,valueof 16 bits which are entered tothe forefrontof the file in order to appointendian.

Becausewith UTF-16and the likeboth of big endianand Littleendianare allowedas a line in the binary digit string, whenthe document is read with erroneous endian, it becomes not be able to decipher. Because of this,readingfirst BOM of the file, the document to be drawn upwitheither endian, after distinguishing high, it reads the text.

As for BOMwhen athexadecimal number at value of 16bits,"FEFF",it readswith erroneous endian, this becomes "FFFE". When BOM it becomes "FFFE", usingthe endianof opposite, if it reads, it is possible to read just. ... The continuation is read

As for BOM not only distinction of endian, there are alsotimes whenit is used in order to distinguish whether or not the document is described with Unicode. Because of this,there aretimes whenBOMhas been attached to the first even in the document of UTF-8 and the like endian there is no relationship.

Unicode with ISO 10646 which almost is equivalence, as for the cord/code which is suitable to BOM it is called "ZERO WIDTH NON-BREAKING SPACE",the binary digit string is BOM being hexadecimal similarly, "FEFF", but it has meant to be possible to appear on the middle of the document.