9.2. What Limits to Choose? A limit must not be perceived as an absolute limit, the implementor is free to increase the limit. To some extent, the implementor may also decrease the limit, in which case this must be properly documented as a non-standard feature. Also, the reason for this should be noted in the documentation. Many interpreters are likely to have “memory” as an implementation limit, meaning that they will allow any size as long as there is enough memory left. Actually, this is equivalent to no limit, since running out of memory is an error with limit enforcing interpreters as well. Some interpreters let the user set the limits, often controlled through the OPTIONS instruction. For computers, limit choices are likely to be powers of two, like 256, 1024, 8192, etc. However, the REXX language takes the side of the user, and defines the limits in units which looks as more “sensible” to computer non-experts: most of the limits in REXX are numbers like 250, 500, 1000, etc.