ISO 259 is a series of international standards for the romanization of Hebrew characters into Latin characters, dating to 1984, with updated ISO 259-2 (a simplification, disregarding several vowel signs, 1994) and ISO 259-3 (Phonemic Conversion, 1999).
ISO 259, dating to 1984, is a transliteration of the Hebrew script, including the diacritical signs (niqqud) used for Biblical Hebrew.
The dagesh (dot inside the letter) is always transcribed with an overdot: ḃ, ġ, ż, etc. The apostrophe (׳) in the table above is the Hebrew sign geresh used after some letters to write down non-Hebrew sounds: ג׳ [d͡ʒ], ז׳ [ʒ], צ׳ [t͡ʃ], etc.