Targeted compression of strings is provided for XML and other documents using local tables whose scope need not align with syntactically well-formed document regions. The local table's scope is fixed (not sliding), and may be nested within other local table scopes. A string is nominated for inclusion, and record(s) are inserted in a document encoding to effect the nomination. The nominated string is placed in the local table in correspondence with a token identifier. During compression, reference(s) to the string's token identifier are included in the document encoding; during decompression the references are replaced by the string. The local table is deleted at the end of its scope. Tables may have multiple channels, with nominated strings placed in a channel based on frequency of references to the strings. The document encoding may include the local table(s), static table(s), and dynamic table(s) in a flat token value space.