As a mother of a severely, learning disabled child, I too had to wade through lots of misinformation. One of the things I learned was that it was a catch phrase. It actually means the inability to read which is ridiculous because even the mentally challenged can be taught to read.
So, if you have difficulty reading or writing you may have sequential errors, visual/spatial errors, auditory or visual memory difficulties, confusion with time and/or transitions, etc, etc, etc. Many of these 'problems' are maturational and given the right teaching methods, can be overcome.
The real problem occurs when there is an emotional overlay which prevents a person from learning coping mechanisms. The best way to combat this is to insure that a child knows that school is only a small part of life and that in the wider world, social skills, physical fitness and emotional well-being will serve you very well. Find out what interests the child and give them the opportunity to excel in something outside of school.
I think of all the time I worried about my son's future and now, at 32, he makes more money than I do and I'm at the end of my career. He's only beginning! He has people working for him that take care of all that "clerical shit" as he calls it and guess what - he is an avid reader and the most literate person in the family.