Range modifier notes

• The offset, depth, offset_abs, and depth_abs keywords are deprecated. These keywords are still supported in IPS Engine 3.0 in order to maintain backward compatibility.
• The Snort/PCRE R option is no longer part of our PCRE. Use --distance 0; instead.
• If you do not use a range modifier with pattern or pcre, matching is done from the beginning to the end of the buffer.
• If you only use distance or distance_abs with pattern or pcre, matching is done from the location that is relative to the reference specified by <refer> to the end of the buffer.
• If you only use within or within_abs with pattern or pcre, matching is done from the beginning of the reference specified by <refer> to the end of the buffer.
• Do not omit the <refer> value or set <refer> to match when performing a pattern search with range modifiers.
• Exercise caution when combining distance, within, distance_abs, and within_abs for the same pattern or pcre. They should be used in pairs of distance/within and distance_abs/ within_abs, and the <refer> values should be the same.