In handwriting analysis, line spacing is important in determining how a person behaves in a working environment, and deals with pressure in handling tasks and decision making. Hence, what writing above the lines means doesn't signify the person's true identity. To understand the person better, a complete handwriting analysis is needed.
It's important to note that hypothesis or theory cannot be proven, it can only be invalidated. Graphology, numerology and astrology have never been scientifically shown to be invalid. Seasoned numerologists and astrologers consistently predict fated circumstances and accurately identify personality traits.
Many times, a simple erasure of words or markings does not completely serve the requirements of an expert forger. He may make further changes to a document by replacing obliterated words or numbers with other words or numbers. A good example of this is changing the amount of a check or altering the date on a contract or will.