Eohlx is the letter x or z.
Anglo-Saxon Rune Poem (from ragweedforge.com)
The Eolh-sedge is mostly to be found in a marsh;
it grows in the water and makes a ghastly wound,covering with blood every warrior who touches it
Eohlx or Algiz in the poem is a large marsh grass with sharp side that, as the poem suggests, give you nasty cuts if you try to hold it or walk through it. I don’t know about you, but it sounds like something ideal to put in a moat and surround a castle or fort or village with. It would certainly make approaching it unpleasant. The world eolh literally means elk, but I had the x on the end to remind myself of the letter it is used for.
Virtually all magical purposes of this rune point to protection. The reasons are various, as are they types of protection, but protection it is. I personally have used this rune for protection magic, in all sorts.. In the case where it shows itself upside down, it indicates a need for caution, for being alert and aware, and to avoid risk or over reaching yourself. This could partly be seen as your usual protection is gone or may not be reliable today, so you may need to rely on other things.
Mixed in there with protection has been seen the moon (probably because this rune proceeds the sun rune) the Bifrost bridge, valkyries (who would protect chosen warriors, but could also aid in sending warriors to Valhalla), elks, a holy sanctuary, and that is about all I can remember without pulling out everyone book and note on runes I have ever had. It is probably one of the most ubiquitous runes used, after Sowelo and Feoh possibly.